Why spend a lot of money on a surround sound system? Well, if it's worth it to you go ahead but what I did was picked a middle of the road model that had a good, solid reputation and all the features I wanted. I believe mine cost around 200-250 dollar and is a Sony.
The only bad part about it is the wired speakers- my house is carpeted and I'm not scared to get my hands dirty so I just ran the wires under the carpeting. Surround sound systems typically have a few modes that can be chosen to emulate different "optimal" settings for movie, concerts (like if you're watching music videos), etcetera.
I prefer to sit in my usual spot and adjust the levels myself because I'm really picky about these things. I chose to mount my speakers directly on the walls (with the subwoofer mounted low on the entertainment system to make the floor shake) at the recommended height for a truly immersive experience.
I love movies like you wouldn't believe. Some of the best presents I've received were from my grandmother, who understood my love of cinema, and made sure to get me gift certificates for the local movie theater. Fast forward fifteen years or so and not only is my grandmother gone but so is that desire to go to the movies on a regular basis.
Movie theaters are usually packed full of rude people who don't know not to talk during the movies. As if that weren't reason enough to stay home, the theaters around here are dirty and far from state of the art. Add to that the fact that my tv and surround sound system absolutely blow the movie theater's equipment out of the water. If Hollywood would let me stream the newest blockbusters directly into my house, I probably wouldn't go to the movies much at all.