this is a hard question...favorite model? hmm...non converted GW i'd have to go with termies, perhaps. they look dynamic, and are plastic for easy conversion.
painting, many of ap0k's work on coolminiornot rank very highly.
see his work here
http://www.coolminiornot.com/artist/Ap0k
hmm. this was a hard question. i'm sure i'll think of a model i like more than the termies though. ...erg.
-ant