I was kind of partial to Kindred: The Embraced, and Wolf Lake. Both of those were way too short. Oh, and I loved The Invisible Man. I was in middle school when that came out and it was the first thing I was allowed to stay up late to watch. I never missed an episode. Soooo bummed when it went off the air.
And not sure if it's sci fi or what, but My Own Worst Enemy is the most recent one for me. I watched that religiously too, and it was cancelled in only 8 eps. I almost broke my TV throwing things around at how they ended it, too. GRRRRRR!!!!