I know this isn't the answer you want, but here it is:
It depends.
There may be many, and there may be none. It's like asking what kind of sauce is suitable for a steak. If the steak is perfect--none. But then again, the steak may be dry and lacking, or there may be a certain flavor I'm going for that requires a certain sauce.
In general, I use a compression (though I control levels just as much if not more by tedious automation--it often sounds better than compression). Sometimes I use reverb, though sometimes I don't. And often I use some EQ, but when I get the right mic for the right voice--even that isn't always needed.
Record a track and post it up. You'll get better (or at least more specific) input that way.