Reaper was a great show!! I was really disappointed when that got cancelled. And I really liked The Gates too, but that only lasted one season
Whenever I get asked whether I prefer Star Wars or Star Trek my answer is always Stargate!
Love SG-1, Atlantis was good but they completely lost the plot for SGU - although Robert Carlyle was, as always, awesome. My favourite ST is Voyager, then TNG. DS9 I just couldn't get into as much although there were some really good episodes. Enterprise was a major disappointment, I stopped watching about 2 episodes in to series/season 2.
I really like Being Human too - I've only seen the UK version so far though so I don't know if the US version is as good. And Vampire Diaries vs True Blood? Vampire Diaries is more 'Twilight'-ey and True Blood is definitely more 'Adult' - and just plain weird at times, which is fun.
Dollhouse, Haven, Alphas, Warehouse 13, Lost - all good.
Once Upon A Time, Firefly, Chuck, Torchwood - really good
A Town Called Eureka ( I think this might just be 'Eureka' in the US), Fringe - really really good
I couldn't get more than a few episodes into Sanctuary, mainly because Amanda Tapping will always be Samantha Carter (Stargate SG-1 + Atlantis) in my head, and also because although she has relatives in the UK apparently, she obviously doesn't spend much time here because the accent really
Farscape and BsG (Battlestar Gallactica) I started watching but kept getting side-tracked so still haven't seen them all, although I did enjoy them and do intend to finish them one day!
Andromeda was ok - bit hit and miss for me.
Babylon 5 I enjoyed, but I don't think I ever finished that either - they ended that one with a couple of specials (not sure if it was a mini series) after cancellation so that they could end it properly.