Let me start by saying that the two shows are polar opposites:
The West Wing is about fundamentally good people trying to do good things in an environment where that's never easy and not always even possible. Even a cynical libertarian like me, who would do cartwheels if the entire District of Columbia slid into Chesapeake Bay, never to be seen again, could empathize with the characters and their situations at times, and right-wing bellyaching notwithstanding, the show went out of its way to present "both" sides of a lot of issues fairly.
House of Cards is about relentlessly ambitious House Majority Whip Francis Underwood (a Democrat), to whom policy is always and only a tool and to whom principles are, on their best days, dangerous and unwelcome distractions. As the series opens, he learns that he's been screwed out of a promised Cabinet appointment and revenge is very much on his mind. Over the course of the first 13 episodes, he ruthlessly runs down everyone who gets between him and his goals. How far will he go? No spoilers, but at least as far as you're willing to believe he'll go, and maybe a little farther. The first volume doesn't end in a cliff-hanger, really, but it does close with the pieces set up for what looks like a political mini-Armageddon in the making. I understand that Netflix has ordered a second volume.
The West Wing is the kind of series I like and don't really want to admit to liking. House of Cards is the kind of series I like and wish I didn't like. Frank Blair makes Machiavelli look like Mother Teresa. At pretty much any moment, you can be pretty sure something is coming that you want to see, but don't want to want to see.
The show has a hell of a cast -- built around a couple of big names (Kevin Spacey as Underwood, Robin Wright as his wife Claire), rounded out with talented up-and-comers (Rachel Brosnahan, Kristen Connolly, Kate Mara) and more experienced actors whose faces you'll probably recognize but whose names may not be especially familiar because they mostly do stage and episodic character work (Ben Daniels, Michael Kelly, Corey Stoll).
Here's where things get brutally simple: You either like Kevin Spacey or you don't.
If you don't (and I know a lot of people don't, and understand why), this show simply isn't for you. The cast is talented and the characters are sometimes compelling, but make no mistake, this is not an ensemble show with equal play for multiple character development lines. It's a show about Frank Underwood (although Zoe Barnes, the reporter played by Kate Mara, does put up a little bit of fight for story share). Even when he is not on screen (and he's on screen a lot), Underwood's shadow looms over every event and development. The show is about how other people interact with or are affected by Underwood, and little or nothing else.
If you do dig Spacey -- and I do -- you're in for a treat. His bombast is ever in full bloom. He frequently breaks the fourth wall to lecture the audience on the nature of power, etc. Spacey tends to dominate anything he's in, and in House of Cards his character does as well.
Beyond that, I don't have too much to say about the show.
The production values, music, etc. don't scream "Emmy" or anything, but I've got no complaints.
No single plot twist has knocked me back on my heels or anything, but there are plenty of juicy little surprises to keep things interesting. I'd like to think I can predict what's coming (I'm usually pretty good at that, and I'll risk one such prediction right now -- next season, I expect Doug Stamper's loyalty to Underwood to be tested severely by the matter of Rachel Posner), but at least a couple of times I've been wrong.
So: If you like political dramas and you like Kevin Spacey, you'll like the show. If you dislike either, watching it would be 10 hours of your life you'd wish you could get back.
