I'm also pretty confused about the 10+ movies and where they all tie in, i'm afraid if I skip them i'll miss something important... What would you guys recommend?
Thanks in advance
The first six movies tie into TOS. Movies seven through ten tie into TNG.
ST The Motion Picture and The Final Frontier are standalone. You don't have to watch anything else to really understand what's going on in those movies, you only have to be familiar with the characters. You might need to watch some bits of TOS to understand what's going on in TMP to figure out the time frame as the movie doesn't properly explain the gap well (IMO).
Though, TOS is episodic so you don't have to worry about a story arc. You just need to be familiar with the characters.
ST The Wrath of Khan, The Search for Spock, and The Voyage Home are a movie trilogy. You can watch The Voyage Home on it's own but the first ten minutes or so will be confusing if you didn't watch TSFS and that movie will totally be confusing if you didn't watch TWOK.
TWOK is the only ST movie in the TOS franchise that actually connects and expands on an episode in the series. So you're better off to watch Space Seed (Season 1) before jumping into TWOK. It's a great movie but you fully won't understand why Khan is so batshit crazy, especially towards Kirk.
Star Trek VI The Undiscovered Country follows, continuity wise, after The Voyage Home in terms of characterization, plots, story, and events. Mostly due to the fact that it follows the world set up by Meyer/Nimoy and his crew (and probably because the studio was trying so hard to forget that TFF even existed). It's also a send off movie so watch it
last.
Generations is another "send off" movie but it's really, really shitty. It's like a Kirk vs Picard team up but done like shit.
Super Sentai does team up better than Star Trek. You're better off watching this version and be done with it:
[yt]http://www.youtube.com/watch?v=vrz8_jNL1a4[/yt]
First Contact, I felt, you could watch it without having to watch TNG. I watched a few episodes of TNG but I enjoyed the movie without being a fan of TNG.
Didn't bother with Nemesis or Insurrection.
As for the series, I watched DS9 as it aired and didn't feel as if I needed to watch Voyager or TNG to understand what was going on in that series. The tie ins are so weak that each show, in my opinion, stand alone pretty well without being stuck having to go back and forth to figure out wth is going on. TOS is obviously stand alone... so yeah, personally, I just watched TOS (when it aired on Sci-fi back in 98 - 99) and DS9 and enjoyed it without having to watch TNG or VOY.