Nemesis was good, but I think the whole problem was Star Trek oversaturation. I always think of 1990 to 1999 as the golden age of Star Trek, nearly all of my favorite episodes are in that time period. But because everyone (Trekkies) had seen so much Star Trek the bar had to be raised to really impress us, but since it was not raised there was disappointment.
I wasn't disappointed, its a good movie to watch, but because of oversaturation Nemisis didn't stand a chance against the Matrix Reloaded, and Lord of the Rings: The Two Towers. LOTR trilogy are the most amazing films of this century, nothing can compare to their epicness. So what chance did Star Trek Nemisis have?
Another problem was that the TNG crew weren't really cut out for action movies. The DS9 crew could have been up to the job, but by then it was to late. (sighs)