Attack of the Clones
Obi-Wan gets captured, Anakin goes to rescue him and gets captured, the Jedi go to rescue them and get captured, the clone army go to rescue them and there's a load of completely unexciting CGI machines blowing each other up, interspersed with Threepio turning out the worst puns since Batman & Robin...and the anticipated lightsaber battle with Dooku is lame. Then Yoda becomes Sonic the Hedgehog - and doesn't even beat Dooku!
So the Jedi achieve nothing, they don't know who the bad guys really are, the huge climactic battles are a stalemate...as Lucas has stated, most of the prequels are padding.