|It's like this...with gold!|
For starters, there's the miner/herbalist. Obvious choice is obvious. Ever since Blizzard allowed you to track ore and herb nodes at the same time, this has been a very popular profession combo. You could even add in Archeology to the mix and sell the keystones that you find. Or just use them to grind out whatever item you want from that hellish profession. I don't much care for archeology, or flying around in circles in general for that matter. If I had one of these alts, it would have to be a druid though. Not shifting from flight form to pick herbs is retarded OP.
A Deathknight enchanter would rank on my list of ideal alts. DKs can steamroll dungeons up to at least Wrath level easily. All you have to do is pick a dungeon that drops items that disenchant into the dust/essence/shard that you desire and go to town. As much as I hate farming ore/herbs, I love going back and revisiting old dungeons and raids. What can I say? I loves me some nastalgia. I actually had this alt for a while, until I decided I needed a third alchemist.
I'm very certain this last one is also popular. Jewelcrafting/Enchanting. I have these two professions, yes. But they are on seperate characters,and it wastes a fair bit of time mailing things around for The Shuffle. If I had it to do all over again, my jewelcrafter would be an enchanter to boot. I have to say that would be ideal for me.
As it stands right now, I have a fairly good alt for my playstyle though. Jewelcrafter/Inscriptionist. Most of my purchases of ore and herbs get prospected and milled, so I can spend most of my "goblin time" on this character. I can browse the AH for deals on other items while processing the raw materials. It's not optimal, but it works.
What about you? What would you say is your ideal alt?