What defines Best?
Most powerful
CC
Most powerful Shooting
Most powerful combined shooting and
CC
Most resilient or survivable
Most powerful for its price point?
Most powerful for a regular game? 2000pts? - 1850 - 1500?
Of course the Emperor Titan is probably the most powerful. But maybe its the Eldar Phantom Titan
Warlord Battle Titan (2850pts) [Arioch Titan Power Claw, Belicosa Pattern Volcano Cannon, Two Reaver Laser Blasters]
vs
Phantom Titan [FW] (2530pts) [Phantom Glaive and Twin-linked Pulse Laser, Phantom Pulsar, Pulse Laser]
++ Profile Summary ++
····
Phantom Titan: WS:3|
BS:4|S:10|Front:13|Side:13|Rear:11|I:3|A:3|
HP:24|Type:Super-Heavy Walker
····
Warlord Battle Titan: WS:2|
BS:4|S

|Front:15|Side:15|Rear:14|I:4|A:3|
HP:30|Type:Vehicle (Super-heavy Walker)
Defense
····
Armoured Ceramite: Description:
····
Eldar Titan Holo-Fields: Description:Whenever a model with Eldar Titan Holo-fields is hit by an attack, before rolling for Armour Penetration, or on the Destroyer table, its attacker must roll a
D6. If the target model moved in its controlling player's last Movement phase and the attacking player rolls a 4+, then the hit stands, roll for Armour Penetration or on the Destroyer table as normal. If the target model did not move in its controlling player's last Movement phase then the hit stands on a 3+.
····
Void Shields: Description:Warlord Titans have 6 Void Shields.
Weapons - as chosen by me for a titan brawl.
IOM
····
Ardex-defensor Mauler Bolt Cannon Turrets: Range:36"|Strength:6|
AP:3|Type:Heavy 6, Twin-linked, Ardex Machina
····
Arioch Titan Power Claw: Range:-|Strength

|
AP:1|Type:Melee, Machine Destroyer
····
Belicosa Pattern Volcano Cannon: Range:180"|Strength

|
AP:1|Type

rimary Weapon 1, Apocalyptic Blast, Machine Destroyer
····
Rear-mounted Ardex-defensor Twin-linked Lascannon Turrets: Range:48"|Strength:9|
AP:2|Type:Heavy 1, Ardex Machina
····
Two Reaver Laser Blasters: Range:96"|Strength

|
AP:2|Type

rimary Weapon 3, Large Blast
Eldar
····
Cloudburst Missile Launcher: Range:48"|Strength:8|
AP:3|Type:Heavy 4, Interceptor, Skyfire, Sunder
····
Phantom Glaive: Range:-|Strength

|
AP:1|Type:Melee, Spirit-shock
····
Phantom Missile Launcher: Range:48"|Strength:9|
AP:3|Type:Heavy 4, Sunder
····
Phantom Pulsar: Range:120"|Strength

|
AP:1|Type

rimary Weapon 4, Large Blast (5")
····
Pulse Laser: Range:48"|Strength:8|
AP:2|Type:Heavy 2
You decide