My newest refinement - Orks 1850
Here's the newest iteration of my 1850 Ork Hammer and Anvil style army. It consists of a fast element that flanks one side (the hammer) and a slower but crushing infantry advance (the anvil) that leave my opponent with nowhere to turn until they're eventually surrounded on all sides by Orks. For a real competitive situation I'd drop the Kommandos for another Nob with a komb-skorcha and 3 grotzooka killa kans to walk in the middle of my slugga mob and give the whole thing 4+ cover saves (while gaining 4+ cover themselves). It's manipulating the rules in an almost abusive way to do so though. However, 30 boyz with feel no pain and a 4+ cover save is sick. They shrug off fire like they were nob bikers.
Ork 1,850 point army list – Hammer and Anvil with Partsmakers
1,850 total – 109 models
Warboss: PK, squig, cybork, bike -150
Mad Dok Grotsnik: -160
15 Lootas -225
9 Kommandos with burna and Snikrot -190
Grotsnik's parts-makers: 30 slugga boyz with Nob with PK and 'eavy armour -220
Dakkaladz: 30 shoota boyz with Nob with PK and BP -220
Objective holders: 20 shoota boyz with Nob with PK and BP and 2x big shoota -170
Nob Bikers: 8 bikers with cybork bodies, painboy w/orderly, BP, Waaagh! banner, PK x2, BC x2 -515
Heavy Support: 0
Fast Attack: 0
Grotsnik joins the sluggas, warboss joins the nobs, and turn 1 everyone but the lootas runs at the enemy waving their arms in the air and yelling, nobs turbo-boost, lootas start taking down light vehicles or important targets. Turn 2 the sluggas keep running and get into assault if they're lucky, everyone else moves and shoots, and the nobs assault. Turn 3 pretty much everyone gets into assault or keeps shooting. Snikrot shows up at some point to kill a tank or dev squad or similar target. When I'm playing objectives the 20-man shoota squad goes for an objective or two and pretty much sits on it or provides fire support for a turn or two and then retreats to the objective.
Other iterations of this army that have served me well in the past have had a 12-man warbiker mob, no grotsnik, and either kommandos in full strength or lootas but not both. I've been playing low-point games recently to prepare for a tourney and have fallen in love with both Grotsnik and Kans.