Insurrection tied with Generations for me, the former just reeked of cost cutting throughout, and was just a below average TNG episode stretched over 2 hours. It had it's moments, but these were mainly humour based, whilst welcome I didn't pay to watch a comedy.
Generations was just an all-round mess plot-wise. but at least had a couple of decent sequances (enterprise B and the E crash) and felt more like a big screen adventure (at least for 1994) but the plot holes as described earlier in this thread killed the film for me, at least compared to my favourite Treks. There was just no need for Kirk to be in it, as the above post says, the end of 6 was a perfect send off for the crew, they should have just made a standalone TNG film