I've not played
40k since just after 3rd was released but I have entered a charity tournament in May and I have gone for Death Guard mostly because it was my secondary 2nd ed army and I didn't feel like remaking my pure infantry guard
Deamon prince: Mark of Nurgle, Nurgles rot = 145
Sorcerer: Mark of Nurgle, wind of chaos, melta bombs = 155
7 Plague Marines : 2 plasma guns, plague champion with power weapon = 221
7 plague Marines: 2 melta guns, Plague champion with powerfist = 221
Rhino = 35
7 plague Marines: 1 flamer, 1 melta gun, plague champion with combi melta = 201
Rhino = 35
7 Marines: 1 melta gun, aspiring champion with combimelta = 140
Rhino = 35
7 marines: flamer = 110
7 Havocs: 4 missile launcher = 185
Predator:
TL lascannon, lascannon sponsons = 165
Predator: heavy bolters = 100
1748
Not exactly 'competitive' but it looks perfectly reasonable to me. I have stuck to the Death guard/Nurgle theme as close as I could without doing anything as crazy as wasting points on icons; hence the lack of wings and obliterators.