All right, I've only done I think one or two Batreps before, but here goes another. Some 'Ard Boyz semi-finals practice between myself (Space Marines) and my main training buddy (Guard).
So..... on to the lists!
2500 Imperial Fists (and drinking buddy!)
HQ
Shrike
Chaplain with Jump Pack
Elites
Dreadnought with Mulit-Melta, Heavy Flamer
-----Mounted in drop pod
Dreadnought with Mulit-Melta, Heavy Flamer (my only proxie as mine is currently in pieces. 'Tis a Carnifex [dreadfex!])
-----Mounted in drop pod
5x Assault Terminator Squad with 3
TH/
SS and 2
LC
-----Mounted in LandRaider Redeemer with Pintle Multi-Melta
Troops
10x Tactical Squad with Lascannon and Melta Gun
-----Mounted in Razorback with Lascannon and Twin-Linked Plasma Gun
10x Tactical Squad with Lascannon and Plasma Gun
-----Mounted in Razorback with Lascannon and Twin-Linked Plasma Gun
10x Tactical Squad with Missile Launcher and Melta Gun, Sarg has Power Fist
-----Mounted in Drop-Pod
Fast Attack
8x Assault squad, Sarg has Power Weapon
3x Scout Biker squad, Sarg has Power Fist
Landspeeder with Multi-Melta and Heavy Flamer
Heavy Support
Vindicator with Dozer Blades
5x Devastator Squad with 4 Missile Launchers
-----Mounted in Razorback with Lascannon and Twin-Linked Plasma Gun
I designed this list directly after designing a friend's Dark Eldar list. I took the idea of in-your-face alpha strike and tried to apply it the best I could to marines. It really is more of a 1-2 punch with garunteed first turn assaults followed by very strong second turn assualts. There is also a sizeable fire base.
2500 Imperial Guard (there are some proxies in this list as we didn't have everything)
HQ
Command Squad with 3 Plasma Gun, Medic, Commander has Plasma Pistol
-----Mounted in Chimera with Hull Heavy Flamer
Command Squad with 3 Plasma Gun, Medic, Commander has Plasma Pistol, Officer of the Fleet
-----Mounted in Chimera with Hull Heavy Flamer
Elites
3x Ratlings
10x Psyker Battle Squad (Vox-Casters as counts-as)
-----Mounted in Chimera with Hull Heavy Flamer (Hell-Hound)
Troops
10x Vet Squad with 3 Melta Guns
-----Mounted in Chimera with Hull Heavy Flamer (grey Chimera)
10x Vet Squad with 3 Melta Guns
-----Mounted in Chimera with Hull Heavy Flamer (grey Chimera)
Platoon Commander with 4 Flamers
-----Mounted in Chimera with Hull Heavy Flamer (Black and blue Leman Russ Hull)
10x Infantry Squad with Autocannon, Commisar with Power Weapon
-----Mounted in Chimera with Hull Heavy Flamer (Black Leman Russ Hull)
10x Infantry Squad with Autocannon
-----Mounted in Chimera with Hull Heavy Flamer (Black Leman Russ Hull)
Fast Attack
Vendetta
Vendetta
Heavy Support
2x Medusa with Enclosed Crew (Leman russ with sponsons)
2x Medusa with Enclosed Crew (One Russ, One griffon)
2x Demolishers (Leman russ with no sponsons)
He told me he wanted to bring a list that would give me a good challenge. The 3 ratlings were 30 points he wasn't sure what to do with.
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Mission: Whoz got da Motz! (central objective one)
Deployment: Pitched battle
The battle field!:
I win the roll to go first (Yay!) and choose my side. My opponent then deploys. He wins the infiltrator roll, deploying the ratlings right in the middle as far forward as possible. I deploy shrike and company on one side, and the scout bikers on the other. I then win the scout move roll and turbo-boost those bikes as far forward as possible. He flat-outs the Vendetta to the center. So now it looks like thus:
Pre-game thoughts 
That is a

ton of tanks. I saw a lot in the list, but on the table it is impressive. I really hope I have enough anti-tank to make a dent. That sneaky git placed his ratlings so that I can't assault his troops first turn. I guess I'll assault my secondary targets, his command squads and medusa. I really don't see many people getting a massacre on this round, so a Major or Minor win will be enough for me.
He rolls to sieze the initiative and gets a.........2!
Spolier Ending (for those who want to know before you read!):
Marines, Top of Turn 1
I land both of my Dreadnought Pods near the center of the board. One scatters way off onto a rock! My plan is to blockade him from ever reaching the center, making my life much easier. Bikes move up to assualt, Shrike and company moves up to assault. Most everything else moves up to increase fire capacity. LandRaider and Vindicator pop smoke.
My actual dreadnought blows a demolisher sky high. My other shooting sees little actuall benifit, getting some shaken/stunned/weapon destroyed results. Shrike and company fleet forwards.
Here is where it begins! Shike and company assualt the Medusas, a Vet chimera, and a commander chimera. The bikes assault a vet chimera and the command chimera. Everything auto hits has nothing has moved yet.
The command squad wifs on the vets, but imobilizes the command chimrea. Shrike and company cause a good bit of damage, but don't actually kill anything, nothing can shoot though.
Imperial Guard, Bottom of Turn 1
This is where it hurts. If I had only caused that much damage as a Dark Eldar list, I would be screwed without a kiss, but I'm marines, so I can take a little more punishment. He moves all the tanks enaged with shrike foward and unloads, hoping to just clear out the assault squad. The vets my bikes wiffed against tank shock them in return. My bike turn tail and run! In the process, the Chimera-o-Vets moves toward the landspeeder to take it out. most things just shuffle around so they count as moving.
Shooting sees six assault marines dead. I really thought he would wipe out the squad, but with Shrike and the Chappy to soak some plasma wounds, they survive. The vets blow the landspeeder to pieces! There is some shaking and I think a vendetta removes the dreadfex's
DCCW. The vets' chimera causes another wound to my scout bikers, making them fall back another
3d6. At least they auto-rally.
Marines, Top of Turn 2
Thanks to the Master-o-Fleet, my drop pod full of troops doesn't enter. I think that was actually a good thing, as it may have blocked my Landraider's path if it had. My bikes turbo back toward the action. I move my melta
tac squad up and unload to hopefully rid myself of a couple of chimeras. Shrike now bears down on the two units who just shot at him. The landraider moves up and unload the termies out the side (there is a reason for this). In the process, it tank shocks the ratlings and sends them packing! My dreads prepare to charge anything within range while the rest of my stuff moves to maximize firing lanes.
My las-
plas razorback destroys a Medusa. My Landraider fires the multi-melta at the platoon commander and blows his ride sky high, pinning him and killing 3 guardsmen. The storm bolters from the drop pods finish off the ratlings. My melta
tac squad imobilizes the vets' chimera and the razorback explodes the command chimera. The termies deployed back so the vindicator could fire. It does nothing to anything, but they have fleet (thanks to shrike) so they fleet forward. My dreadfex multi-meltas the last demolisher, killing it. The other dread, which can't shoot, fleets toward the vendettas.
Shrike bends both squads over and lets them have it, wiping them both out. The termies hit an infantry chimera and proceed to blow it up, killing a few guardsmen along the way. My dreadnought blows a vendetta sky high.
Imperial Guard, bottom of Turn 2
Guard decides to GTFO of the center. He prepars some fire from the medusas and tries to bring the vets over to take care of some dreadnoughts. The Psykers really don't have anywhere to run to. The remaining vendetta got imobilized somehow (I think by a lascannon squad.)
His little open guard squad fires into the termies bearing down on them and kill a lightning claw! They may now die happy! Now, I'm sure you've heard of Danger Close. If not, play some MW2. So guard decides that since I am too close to the chimera to legally hit my assualt squad, he is going to fire at my termies with his medusas... He knows the guard squad is there, he is sure it won't scatter that bad.... His first shot goes back toward my edge and hits two termies. His second shot goes towards his edge hitting two termies..... AND 7 GUARDSMEN! He rolls to wound my 4 termies getting three 1's and a two, I pass my
SS save. I roll to wound his 7 guardsmen, wounding 7. He goes to ground (from his own shot) and makes his saves, LOSING 6! They then proceed to run strait off the board! (In hindsight, doesn't the commisar have something to do with excecuting somebody instead of running?) So his shooting phase sees a total of him killing his own squad.
Marines, Top of Turn 3
It's nearly over, he doesn't have much left. My droping squad arrives this turn right next to the objective. (Wall complete, though unneeded) My combined shooting sees me destroy all the remaining chimera except the one next to my assualt squad and the pysker chimera. I also destroy all the remaining tanks except the medusa near my dreadnoughts. My dreadnought runs to assualt a freshly presented command squad.
I move in and assualt both chimera, destoying both, and wipe the command squad with the dreadnought. He now has 3 units left: A pinned vet squad, a pinned infantry squad, and a psyker squad.
Imperial Guard, Bottom of Turn 3
The psyker squad moves away from the termies and shoots them, getting
AP 1 and killing the last lightning claw. They hang around though. The last medusa also decides to not scatter this phase and destroys a razorback. Sad day.
Marines, Top of Turn 4
I focus fire on the last medusa, and blow it up. I assualt the last remaining squads, and wipe them all out. Guard is tabled. I play the remaining turns to earn the victory.
Result:
Marines win with a 24 point Massacre!!!!!
Hope you enjoyed! Good luck all at semies.