I could go on for a week talking about some of my favorite sci fi couples, but I thought I'd end with these two.
Buffy the Vampire Slayer
I did like Angel when his character was on the show, but he wasn't right for Buffy. Spike, now there was a man, err vampire. I think I tend to enjoy smart-ass characters, being somewhat sarcastic myself and Spike more than fit the bill. Plus he's GORGEOUS. Buffy didn't know a good thing when it bit her on the neck.
Doctor Who (new)
I haven't seen season two of the new Doctor Who. CBC is about six months behind the BBC. So this October I'll get to see if the chemistry between Rose and the new Doctor is as good as the first season. The tension was subtle until the last episode where things exploded - literally. If you haven't had a chance to check out this series, do yourself a favor. :)
I hope you've enjoyed looking at some of these couples with me. Let me know if you have any favorites that I missed. :)