My gripe with Nemesis is that too much of the character-oriented screen time ended up on the cutting-room floor, and too much of the rest seemed overshadowed by the filmmakers' unholy determination to make sure the viewer knew s/he was witnessing the Biggest, Longest Star Trek Space Battle Ever (TM). Well, and then there was Picard's Substitute Penis (TM), a.k.a. the Argo jeep, which made no sense whatsoever either in terms of Picard's character or in terms of Starfleet protocols ("To heck with the Prime Directive! I feel the need...the need for speed!")
But seriously, the nature vs. nurture dualism of Picard vs. Shinzon had so much more meat to it than the space battle...and Stewart and Hardy both seemed up to the task to me. The excessive focus on the FX and the militarism and the hackneyed save-Earth-from-poorly-rationalized-alien-attack thread wasted what could have been a really great character showdown.
It is by caffeine alone I set my mind in motion. It is by the juice of java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion.
--Mentat Coffee Mantra