This one was great.  But be warned.  There's only one season before it got cancelled.  However,  a movie did get made like 8 or 9 years after.

What, Serenity is from next year?

Well, yeah, Firefly is a pretty good show, and it is a 'western'-style sci fi story. Clever writing, good dialogue, and likeable characters. I do recommend that one. Think of it as 'Han Solo as written by Joss Whedon.'. And yes, Farscape was also quite watchable and then some. I'll second that recommendation.

Stargate is a bit more iffy, the first series is rather outdated, but Atlantis and Universe is decent enough; I'm liking Universe quite a lot.

A recent sci-fi series at least worthy of a mention is 'V'. You might like it, and the old folks might have seen the series it's a remake of.   
Trailer: (http://www.youtube.com/watch?v=ahjPQjQGdbU). (I didn't like it but it did get a second season, it may have picked up after I stopped watching.)

As for other science fiction series.. an animated one, but not at all childish, is Ghost in the Shell: Stand Alone Complex.
Intro: (http://www.youtube.com/watch?v=rUk2r-cJtTs&playnext=1&list=PL15C1A552829C3E01&index=1). Very heavy, philosophical, and at times quite strong. One of the best series I've seen.

Star Wars: The Clone Wars (recent, not the old one) is an animated series based on Star Wars, and should appeal to both a young audience and older. I thought it was better than movies II and III, for what it's worth, but unlike Ghost in the Shell, it is targeted at a young audience.

If you don't need the series to be SCIENCE fiction, but just fantastic in some manner, I would strongly recommend The Walking Dead, which is probably the best new series of last year. True Blood is also well worth watching, as is Heroes. First season was the best one, IMHO, but still.

I liked watching the Farscape series. A little campy but good fun.

I am surprised no one has talked about Buck Rogers.  Wilma Deering is worth the watch!  The show itself is average.

Caprica got the axe. The good part, from my understanding, is that they knew far enough in advance that they had time to make the last couple episodes actually end the show. But, there's only like 12 episodes or something like that. It was doomed from the start. SyFy wanted it to attract female viewers (they said so themselves) so they made it more like a soap opera. Unfortunately for them, that put off many of the people who liked BSG. Whatever new viewers they might have gotten wasn't enough, and Caprica ended up a failure.

I saw the first couple, and didn't really like it. The only part I found interesting was the creation of the Cylons, everything else was kind of "meh." The characters weren't too interesting, and neither was the plot. I gave up on it.

However, there is another BSG prequel in the works, called Blood and Crome. It's about young William Adama in the first Cylon War, and will supposedly be more similar to BSG than Caprica was. At the very least, it will bring back the space combat

yeah - I'm a bit bummed that a few of my fav's... actually all of them, were cancelled off.  Firefly, sara connor, and caprica. 

Yeah - the wrapped things up at least somewhat decently.  I'm really annoyed with the bs they pulled with bill adama though.  Pretty stupid and flimsy, but liked everything else.

going to look into this.  First I've heard about.  I, personally, can't get enough bsg.

This article basically has everything everyone knows about Blood and Chrome (I mispelled it before ): http://www.tvsquad.com/2010/10/22/syfy-adama-blood-and-chrome/

It's going to start as a 2-hour made for TV movie/pilot, and if it's good enough they will turn it into a full show. Unfortunetly, the pilot won't be until the end of this year at the earliest, but early next year is more likely. So we still have a while to wait...

Everything scifi is getting axe these days> first Flash Forward, then Caprica and now SG Universe.

Anyway i concur Raistlins recommendation of Babylon 5 {did i say it right? LOL, my english sucks}. Anyway, you already saw DS9, so B5 is the next best choice. You really wont be disappointed, its the best of the best. Its only weakness is the first season, so do not let it to "scare you away", the other seasons are worth it.

BTW i just finished watching whole Star Trek Voyager and i can recommend that one as well, its maybe not as good as DS9 {its close though, DS9 edges it for me with those huge space battles}, but if liked DS9, you would like Voyager as well.

And indeed Stargate, some people do not like it, but i personally always enjoyed it. Just be sure to start with SG-1, its not only the first one, but imho the best one as well.

I vote for Sopranos.

1.  it is fiction, so it satisfies the "fi" segment

and

2.  it provides entertainment but is politically correct (hence satisfying the 'science' segment) as it shows the mechanisms to how corrupt humans can become whether they obey the badge (ie, law enforcement) or hide from it.

*(being corrupt is not our natural state of existence and neither is living subject to human law)*

Obviously I love the drama/thriller genre, but I especially love the sci-fi genre...but not so much for it's entertainment value.

You see, "sci-fi" to me is in many ways NOT just a movie.

Spaceships are real.

Aliens do exist.

Giants do remain dormant under the crust.

In fact, we are the AI we seek to create. 

Our creators will return to salvage what became of us and this planet, but only to reset things to another beginning.  So again, we will [eventually] become enlightened and take on "civil" measures once again, only to return to our most "natural" state of existence...that being with assumed guidance per the local civilization as determined by the illuminated....ie, slaves.

Make no mistake about it.  We constantly receive these messages/warnings within the highly engaging sci-fi flicks.  The only problem is, we are culturally persuaded to assimilate to a certain thought process and accept these 'messages' as entertainment only....  Hence, "....it's just a movie."

Sopranos.

-.-

yeah - if you haven't watched this, you need to start.  You can buy the entire season digitally through amazon for like $12 if you missed out.