Well, I have a boss GT-3, and a buncha plug-ins for cpu too. Let me tell you, the Boss does wonders for guitar AND vocals. I'm not going for pro sound, though it sounds like that on the recordings, however not like that live, but it sure as hell sounds fine to any non brilliantly ear trained people. (i'm not saying I am). CHeck it out, its raw.
I enjoy putting Metalizers, Flangers, Wa's, and some nice bare distortion can be a really cool effect (check out track 9 on the At The Drive In cd, it's great example of that). Chorus is always a nice lil fun thing to do, and I guess ring modulators are a bit strong sometimes, but can really really make you sound robotic and neat. Its sorta cool to fool around with the Antares Mic Modeler plug in I have too. Ow my cat just jumped onto my crotch from a 5 foot higher shelve, that really really hurt. I don't know why I just posted that, but it hurt and I think I need credit. Well, anyway, also check out effects packages such as Waves Gold Bundle, it'll have all the cool plugins you'll need for voice. However, I'd recommend
the Boss GT-3 for VOCALS AND GUITAR above any pod, any day (i think line 6 is just too computerised, the boss has way many more banks, and all sortsa cool effects to put on your vocals, in cluding harmonizing on 3'rds, 5ths, octaves, pitchshifts, metalizers, ring modulators, flanges, choruses, several different types of each, and way more, and no, I don't work for them, I just really like this product in particular, can get it at Zzounds for like 3 hundred)
For cleaning up I just use compression (of course) and reverb.
Peace Out