i have three alchemy x-mute spec. +600k gold.
Alch for the truegold cd Muahahaha
Inscription. It costs about 2k and takes ~2 hours to powerlevel it, far faster and cheaper than other crafting professions. In the next 1-2 weeks you'll make back more than 2k selling the stuff you made while leveling it. Best of all, you don't have to do Deepholm for a shoulder enchant.
I'd say alchemy. For sure it would be a profession with a cooldown (the more valuable the cool down the better). In WOTLK that was alchemy or JC. Now alchemy or tailoring. The consensus seems to be alchemy.
The only other consideration might be enchanting if you run that particular toon through a lot of instances with BOP items (otherwise you just mail them to your one enchanter of course).
Eng is a good one. Not for money, for fun.
Time...line? Time isn't made out of lines. It is made out of circles. That is why clocks are round. ~ Caboose
I have 2 engineers (3 if you count my 70 twink) for the bonuses and 2 blacksmiths. I like blacksmithing for the extra sockets and for the 365 weapon patterns to make money with. The only problem is you need to run heroics and win rolls for the chaos orbs. Like others have already said, alchemy would be a good prof to have multiples of due to the specializations.
And now you see that evil will always triumph, because good is dumb.
Alchemy, I got 3 with it. Current 2 transmute, 1 flask, will likely go all transmute if epic gems are transmuteable again.
My vote is with alchemy as well =) The transmute is a good steady income.
Alch for sure, tailoring maybe.
I have engineering on 3 of my 6 lvl 85's. Not for the moniez, but for the fun