[thufir]

Tank - warrior, paladin, shadowknight. If you are not planning to raid the knight classes are better tanks than the warrior because they have better snap aggro. My personal preference is SK, but roll an ogre or troll if you choose SK, and do yourself a favor.
Healer - cleric, shaman. Cleric is great for CH and rez. Shaman is a super-powered catch-all with the ability to do anything.
CC - bard, enchanter. I have been grouping a lot with a bard lately and love it. You might too. But you need one or the other to do anything you want reliably. Enchanter is more traditional. Bard requires a lot of work, but is very rewarding.
DPS/catch-all - shaman, rogue, monk. Shamans are really ridiculous. I include them here because you will be sad without one in the later game. Between their massive slows, buffs, debuffs, dots, and backup healing they are awesome. But rogues have the best DPS in the game, and monks are great DPS with pulling power too.

If I had to pick myself I would go shadowknight, cleric, shaman, enchanter. DPS classes are prevalent, so if you feel you need a 5th, you can grab a pug monk or rogue pretty easily. Remember that EQ is a game that requires people to select specific roles if you really want to explore things.