Preference, roughly in order:
AT infantry. In love with ranged AT, though loved this even using just Geballte Ladung and the mini-nuke called Thermos
Engineer. Like to run around repairing (makes me feel like a part of the team even if I don't get any points for it) and manning the AT guns.
Tanker. Have to practice long-range cannon fire, but infantry-mowing is always satisfactory
MG gunner. MG42 is teh king, but Bren/BAR ramboing is fun as well.
Assault. Because I'm a lousy shot, it's nice if you get a second, third, fourth, etc. chance as well
Vanilla. Fun, but not as fun as the others.
The "not so much liked":
Recon. Me: "Is the spot good?" Arty: "---" Moar teamplay would make this more fun.
Arty. Not my cup of tea, especially since the spots I get are 90% of the time bad, or aimed so much above ground that my rounds fall all over the place.
Pilot. Should really configure joystick and practice in SP before doing this more.