Studio speakers are a good way to go.105dB spl .... 450w powered my Behringers are.
Mackie make some good stuff too.
I use mine for mixing, listening, movies and gaming.
As good as active monitors might be, they're going to be a pretty limiting choice if what you're after is a general home entertainment setup.
If you want the option to expand to multi-channel surround later on, and use a wider range of input sources I'd definately be looking at a basic receiver and a pair of front speakers.
If the budget doesn't stretch to decent speakers
and a receiver, you could always just pick up a cheap amp to run the stereo setup to start with, and then grab a receiver later on when you get more speakers, or more sources.
That said, this is coming from someone who runs their telly through a HTiB setup, and I haven't been bothered to upgrade that yet; I've been tempted by the idea of some nicer fronts to take some of the load off the sub but can't justify the cost. It's a small room, and for telly/movies/games the sound is fine.