Fanfic recs? Let's see...
TNG: I'd add Naraht, but she's been added, several times
. Another great TNG writer is the author of the mammoth Echoes, still ongoing at ASC...
Truth is, I've read so much now that I'm suffering from it-all-runs-together-itis.
MC Moose- superb Janeway characterisation. (see ASC Archives)
Kira 47 on Fanfic.net- shippy, but beautifully written.
Kerry's 'Voyager Days' series. This is mostly J/C, but friendship rather than romance, and they're very funny- may be accessible through J/CVille. (oh dear. I think I'm going to crawl under a nice rock now, having declared myself to be a thorough shipper..)
Just realised I've actually recommended more VOY than TNG, even though TNG is my first Trek love! I suppose I'm more critical now; with a lot of the TNG/P/C stuff I was thinking, 'whoo hoo! free stuff to read and lots of it' and as long as the SPAG/GAPS was ok, I read it. Often regretted it too.