I too will have to see it a second time to determine where it ranks vs Jedi, but I liked it. Sure, you can criticize it for the reasons all 6 of them get criticized (wooden dialog, crappy love scenes, annoying kid stuff) but really the movie was about as good as it could possibly have been, provided the "future" was already determined.
I was surpised how much better the CGI was than even the last installment. Sure, it still didn't look real, but almost all of it looked plausible. I'm still perplexed by his tendency to use CG even in places it doesn't make sense and isn't required, but overall it was well done. Ironically my one complaint is that this time around the lightsabers looked a little too neat, clean and "perfect"- I felt they shoulda had a little fuzz to 'em.
Overall, I have to knock off 1/2 to 1 star just for the obnoxious elements (wookies doing the 'George of the Jungle" Tarzan yell, Keystone Cops Droids, laugh out loud love dialogue), but it's still a solid 3-3.5. With each of the other new films, seeing them just made me want to see real Star Wars- with Revenge of the Sith I really though it felt like I was watching Star Wars. I guess in the end that's the best compliment I can give it.