Any list like this would be lacking if it doesn't include Firefly on it somewhere. Granted, it only survived one season before the dunces at Fox cancelled it, but it's still a very, VERY good show. Space Western by Joss Whedon... what's not to love?
I agree with Dexter and Battlestar Gallactica. Gallactica got progressively stranger and more religious into the later seasons, but even then it was still very good, just not AS good (when being judged as straight sci-fi) as it started off. I also quite enjoyed Farscape. Surprisingly good show, produced and featuring creatures made by Jim Henson's Creature Shop.
House of Cards, obviously. House of Lies, too. Oh, and Lie to Me (still upset that one got cancelled, was an excellent premise, superbly cast, and really well written.)
Then of course you have everything with the word "Marvel" on the tin. That should pretty much go without saying at this point.