I'm running a little late on this one. Mostly May's offering finales, but there's a couple Syfy movies, a second season for BBC America's Ashes to Ashes, and Fox is airing the final episodes of it's cancelled reincarnation series, Past Life.
For more on the season finales, check out my article in Sci Fi Wire, "Your complete guide to Sci-Fi TV season finales".
Here's what you have to look forward to this month:
Wednesday, May 5:
Ghost Hunters (Syfy) 8 p.m. - Season six mid-season final
Saturday, May 8:
Mongolian Death Worm (Syfy) 9 p.m. - Okay, this Syfy original flick is not the classic that Mega Piranha was, but you can't have everything.
Tuesday, May 11:
Ashes to Ashes (BBC America) 10 p.m. - Second season premiere
Thursday, May 13:
The Vampire Dairies (The CW) 8 p.m. - Season one finale
Supernatural (The CW) 9 p.m. - Season five finale
Friday, May 14:
Smallville (The CW) 8 p.m. - Season nine finale
Tuesday, May 18:
V (ABC) 10 p.m. - Season one finale
Thursday, May 20:
Fringe (Fox) 9 p.m. - Season two finale
Friday, May 21:
Ghost Whisperer (CBS) 8 p.m. - Season five finale
Medium (CBS) 9 p.m. - Season six finale
Saturday, May 22:
Legend of the Seeker (Syndicated) - Season two finale
Lost (ABC) - "Pilot" - ABC is airing the $10 million dollar original Lost pilot. I'm sure there will be some goodies that tie up things with the finale in one way or another. And it's a good way to get some ratings on a Saturday night to get back some of that $10 mil.
Witchville (Syfy) 9 p.m. - A Syfy original movie that even I, a lover of bad movies, can't bear to put into my DVD player to watch.
Sunday, May 23:
Lost: The Finale Journey (ABC) 7 p.m. - A special exploring what it took to make the series with interviews and a look at the past six seasons.
Lost (ABC) 9 p.m. - 2-1/2 hour season six series finale
Jimmy Kimmel Live: Aloha to 'Lost' (ABC) airs immediately after the finale. It will feature Lost cast members and showrunners Damon Lindelof and Carlton Cuse.
Monday, May 24:
Chuck (NBC) 8 p.m. - Two-hour season three finale
24 (Fox) 8 p.m. - Two-hour season eight series finale
The Big Bang Theory (CBS) 9:30 p.m. - Season three finale
Thursday, May 27:
FlashForward (ABC) 8 p.m. - Season one finale
Friday, May 28:
Past Life (Fox) 8 p.m. - Returns from hiatus with new episodes. In other words, Fox is burning off the three or four episodes that never aired.