Star Trek Fan Films

I'll be honest. I find the majority of them to be sub-par. Anything set in the 24th century so far that I've seen just looks bad with shoddy green screen and often unbelievable characters. The best, but still clunky is probably Intrepid. Though as they are from Scotland/North England they all sound like they're from that region, so you get a weird vibe from it
Stuff set in the TOS Era fares a little better, only because they usually have actual sets. But often the acting lets it down. Farragut, and New Voyages' acting is often not so good, breaking the immersion. When New Voyages became Phase II, the acting seemed a little better, but their latest offering "Kitumba" was the first time I didn't notice them "Acting" And hey it had Buck Rogers in it.
Star Trek OGAM - the less I say, the better. It was an embarrassment to everyone involved.
Star Trek Continues suffers from the acting problem to a lesser extent. I almost believed Chris Doohan was Scotty, but Vic Mignogna sometimes fell into William Shatner playing Kirk, which pulled me out of it a bit.
The best all around effort I have seen in Trek fan films is Starship Exeter - The Tressaurian Intersection. (Their first episode the Savage Empire was simply too cheesy for me to enjoy) Unfortunately TTI is still not finished after 8 years.
Out of all the fan films I prefer the TOS ones that aren't on the Enterprise. I find I can forgive more if it's not people trying to be Kirk and Spock. Let's be honest, unless you go for something completely different, you aren't going to be able to pull of Kirk without it feeling like parody.

As for Trek audio, I listen to Star Trek: Outpost. It's probably one of the best things produced fandom wise. That's not to say they haven't made screw ups. I've heard on more than one occasion, them using text to speech programs for a voice in an episode, and it sticks out like a storm-trooper at a Trek Convention. Apart from that, it's the most solid effort so far.

As for upcoming Trek fan efforts, I am blown away by what I've seen so far from Star Trek: Axanar. (Battle of Axanar) Set twenty odd years before TOS (2245) they are going with a fusion of TOS/Abrahms-trek (notably the Kelvin design aesthetic) and Enterprise. They currently have Gary Graham, JG Hertzler and Richard Hatch on the project.
Axanar is going to be a one-shot, a movie. I haven't seen the weak point of the production yet (the acting) but I don't think they've filmed anything yet. Oh and Captain Garth (Garth of Izar) will be portrayed by Alec Peters, the founder of Propworx, who is the one who's been at the helm for this project.

Also apparently we'll get to see the Enterprise in drydock. 2245 is the year she was built. I don't care if the rest of it is shoddy, but I just want to see the Enterprise being built.