Personally, I'm partial to orks, dwarves and humans. I have never managed to keep an elf alive more than 3 sessions. not sure if I'm just cursed or can't get into the keeb mindset. As for trolls, our group is usually troll heavy and as a result I try to throw in a bit of racial mix to keep things interesting.
If I had to pick just one race,though, I'd say Dwarf. got a soft spot for the halfers. decent racial bonuses for the cost of the bp. Can fit pretty much any role the team needs. Only problem I have seen is getting on rides at amusement parks.
"What do ya mean, I can't ride the roller coaster,you drek head! How bout I tear your knee caps out, and shove that little chipmunk and his meter stick right up your hoop?" - Wayne"Wingnut" Bertolli- Dwarf street sammy-