Episode I sucks for me because the CGI doesn't hold up as well. Jar Jar was film wreckingly awful and Liam Nesson, who is usually badass, feels ridiculously wooden. Lots of embarrassing scenes like Boss Nass blubbering, the "woaoooooo awesome" bit where Anakin steals the Naboo fighter, and the weird Queen Amidala pedo love interest. Side characters such as Captain Tanaka and the two Federation bad guys were also lame. It had a cool theme of military occupation though and I loved the deployment scene of the battle droids (even if the ensuing battle felt like something out of a Games Workshop duel).
III was far from as bad as Episode I, but I just did not like how Anakin's transition to Vadar was handled ("Nooooooooo"). He acts like an angsty teen rather than a badass. The fight with Obi Wan was pretty damn lame, particularly all the talking. The genocide of the Jedi was also confusingly simplistic in its portrayal. A lot of stuff, like Kashyyk, felt like fan service thrown in because Lucas thought "shit, we gotta give the people some Wookies to show continuity between the two trilogies". Spawned a really awesome Clone Wars cartoon though.
Episode II gave us Count Dookake as well, remember that!
