I wholly recommend druid.
My main and most beloved toon was druid ( left after BC, so his at 70 ) and let me tell you I miss the lovalbe cow some time. Playing a druid is FUN. It's not the e-peen class, you won't lead the dps boards or be the must have class. But you'll have fun.
Druids do it all, so you can be a rogue until you get sick of it and then respec to a healer, and with this new dual-spec I keep hearing about, hell, you can be both.
But the real fun is from the hybrid moments. Now, I know a lot of min/max players will disagree with me, and by the numbers they are right. If you are dps spec and gear, anytime you are healing you are not optimal. However, nothings more fun then doing dps, watching a healer go down, shifting out ressing and innervating the healer and then going bear and offtanking until he gets the MT back to full health, then shifting cat and doing dps again. Congrats, you just saved the attampet.
Druid. Cuase we are furry.