Jar-Jar is really the weak link with the first one. Take him out (I haven't seen THE PHANTOM EDIT yet but apparently it's an improvement) - or, more rationally, ignore him - and you're left with a movie that's weaker than the originals, but not massively so, and is a perfectly serviceable action/kid's movie.

Eps II and III, on the other hand, really do suck monkey balls on almost every single level. The dialogue in Episode I is weak, but in II and III it feels like Lucas just gives up and lets some kind of macro on his word processor generate it all. The best bit in them is the scene in III when everyone shuts up and Williams's music takes over as Anakin goes postal on the other Jedi, not because the scene is well set-up (it isn't), but because no-one's talking arsecrap over the top of it. Also, Jar-Jar is a more compelling character than Adult Anakin

So in summary, Ep I > Ep III > > > > > > Ep II.

And the first two KNIGHTS OF THE OLD REPUBLIC games (even the ropey, unfinished second one) spew over all three of them. There must be some fanfic somewhere where HK-47 meets Jar-Jar, surely?