I think the idea of doing post-Nemesis films with a mixture of cast from all three 24th century series would have been a good idea.
That is so fan-wank, but I had that fantasy back in the day.
I started writing this story back when I was in college. I think it's somewhere under my bed - 30 pages typed, and then I stopped.
I remember I took the old TOS film VHS tapes (which formed the Enterprise when placed together in order) and moved them away from each other a bit to form a mega warship (which today, of course, smacks very much of USS Vengeance). I think Voyager was still on the air at the time. I had this idea that Starfleet had been secretly building this huge warship in the shadow of a distant moon, stole some advanced cloaking technology, all in preparation for a war with one of several possible enemies - the borg, the founders, the romulans - and then they actually ended up going to war with the klingons instead. A mysterious general who came to power out of nowhere convinced the klingons that there can be no warriors without war. I felt the story was epic and far-reaching enough to include characters from every 24th century series. I hadn't seen all of DS9 at the time, but now I'm sure Section 31 could have been responsible for the warship.
Don't hate - I know it's cheesy! I was a kid, okay!