With an apartment-grade home theater system, I'd probably look to a "home theater in a box" solution of the 5.1 channel variety.
I personally like Onkyo equipment, and also personally like to look for manufacturer refurbished items to save a buck. This meets both of those factors. Not a hardcore recommendation, or endorsement of this site (though I have purchased several things here), just a suggested starting point:
http://www.accessories4less.com/make...ge/1.html?c=ul
I have a very expensive Polk Soundbar + subwoofer upstairs, in an area where I had no rear walls to mount speakers. Yes, it sounds better than stereo or TV sound, but nowhere near as good as having true surround speakers. If you have the ability to have 5 separate speakers, you will be much-better immersed in the sound-field. Especially at low volumes. Soundbars tend to need to be turned up a bit to accurately simulate the surround noises - bad for your apartment setting.