If I have a lot of chips at a 6-handed table I'll play them aggressively. If you hit your ace on the flop 6-handed and there wasn't a raise in front of you, chances are you're sitting pretty.
However you have to be careful of crafty players who limp in with a better ace. I would consider hands up to AT ace rag, and I really hate playing AJ. So I'd probably limp with AT or AJ or do a small raise preflop, but if it's an action table and I think I can limp and get raised, I'll also call with AK or AQ.
One benefit of having the A-rag is that when your kicker hits nobody puts you on it. From late position 6-handed I'd raise if there were no raise in front of me trying to steal the blinds. But it depends on who's in the hand against me.
Online if my tracker
tells me the big and small blind are playing a very small amount of hands, I'll raise to try and take down their blinds. Aside from that I find the hand very difficult to play, because when you hit you must bet and a raise can be sneaky. Or you can check. You sneaky dog.
In live games, I ussually play 8-9 handed, and tightly, and thus I must play fewer Ace-rag. Unless they're suited. In one of my better live come-ups I was folding AT if it wasn't suited, and just calling with AJ. I know that's a passive and weak way to play the hands, but I was really just waiting for the nuts. And it's really hard to make the nuts with AJ, 9-handed.
Luckily in small-stakes live games, a lot of people don't pay attention to table image, so they're more than likely willing to pay you off for being a tight player.
Any suited Ace deserves a call if there's only one raise ahead of you.
Now that that little note is done, I'm pretty sure you could quote me and find at least 8 contradictions. Guess it depends on what you're playing, who you're playing against, and how your stack is.