Heh, I tried writing a post that fills your preferences but it's too large a project for the time I've got on hand. However, I do have a list of sci-fi that I'd recommend from earlier, so maybe something here you'll like?
WORTH WATCHING:
1) Firefly; it's simply awesome. Watch it now! Go!
2) Farscape; a Sci-Fi series filmed in Australia (including my home city! Yay!). It's obviously been made on a budget and you can tell, but it's brilliantly written. It's bizarre, utterly mad and doesn't take itself too seriously. One of my favorites, I beg you to watch it. Oh! And the Jim Henson Company does awesome animatronic puppets for the aliens. Watch it!
3) Stargate SG-1; the start of a couple of other shows of note. It takes a while to really get into the swing of things, as stupid looking sets and costumes undercut it's more serious nature. It also suffers from a weak main plot arch in the final seasons. Mostly notable for its better spin-off. That said, it can be a lot of fun. There's also a shit ton of stuff to watch here as well, coming in at more than 200 episodes.
4) Stargate Atlantis; the best of the Stargate franchise in my opinion. It has the same sense of adventure SG-1 has, but with overall stronger production and writing. If you can't get into the SG-1 I'd still give it a shot.
5) Stargate Universe; the final Stargate spin-off series, and the shortest. Unfortunately, it really jumped on the dark and gritty feel of the very successful Battlestar Galactica and it couldn't pull it off. It's worth a look if you've got a lot of spare time.
6) Battlestar Galactica; a dark and gritty Sci-Fi series which, unlike most of the others here, isn't about adventure but rather survival. Its writing is almost consistently excellent and it's got some great space battles. Apart from Firefly and Farscape, it's one of the only TV series where I've bought the entire thing. Oh! And it ended, rather than being cancelled. You don't usually see that.
7) Caprica; the drama spin-off to Battlestar Galactica. I'm actually not sure why I like this one so much, but I can tell you I did. It's a rather interesting drama that is technically a prequel to Battlestar Galactica, but I'd still watch it second.
8) Terminator: The Sarah Connor Chronicles; it's not one of my favorites, but it's still pretty good. Unfortunately it ends just as it brings in a major plot arch which is a little bit of a kick in the balls, but it's still worth watching overall.
9) Fringe; an investigation series based around all sorts of crazy science that can be a little contrived a times but can be forgiven purely because of some of the better episodes with Walter Bishop (a genuinely mad, drugged up scientist) .
10) Sanctuary; it's a supernatural series that doesn't always hit the mark, but it's usually interesting. Notable for using almost all CGI sets. It's got a steam-punk vibe and worth watching if you've got the time and like monsters and general supernatural stuff.
11) Dark Angel; It's got an intriguing premise (a post severe EMP world), but the writing fails it after its second season ? and it?s not amazing to begin with. If you do like the series, don't watch the second season for the sake of your sanity. On the plus side; the setting is great and the action is usually pretty enjoyable. A lot of stuff gets blown up, too.
12) Jericho; a post-apocalyptic TV series that, while took a little while to find its feet, it's actually really good. There?s not much to say about it, except that it focuses on what would really happen to a small town if nuclear war occurred.
13) Doctor Who; I'm always hesitant to recommend it, because I'm not sure where to tell you to start watching. The start of the reboot, or whatever they called it, is awful. Yet I'm not sure where else they set up the premise. Opinions on it are always very polarized as well - either you love it or you hate it.
14) Andromeda; while it starts as a promising-but-flawed series it drops it?s lead writer after the second season ? and you can tell. It drops its continuity, changes a lot of the characters and general tone of the series (sigh, fucking space magic). If you?re really into space opera and want to watch it past its second season, jump to near the end of season three. It gets slightly better, though it?s still pretty jarring. If you don?t, the first two seasons are worth watching just because Lexa (who plays the ships AI) is pretty awesome.
15) Falling Skies; yet another hit-and-miss post apocalyptic series. This time it's aliens, and it's not horrible. A lot of the twists are stupidly predictible and it falls into the same pit as most post apocalyptic shows where there will be whole episodes where just nothing happens. It'll probably end up on the "not worth watching" list if it's second season doesn't get any better.
16) Red Dwarf; the British one. We don't talk about the American one, okay? Otherwise, this series was hilarious despite - and sometimes, because of - it's low budget. This is one of those shows that you must watch. Do it!
17) Continuum; holy hell. I really was blown away by this series, particularly amazing because I wrote off it's premise of "a cop travels from the future to our time" as awful - no matter what they did with the show. Little did I know that I'd get a serious sci-fi show discussing the ethics of corporations, and their increasing power in politics of some western countries. It has some really intelligent moral discussion and some extremely well written characters. Certainly a must watch.
