If you aren't looking to spend 1000 dollars on speakers.
I would suggest the Infinity Beta Series if you are on a budget. I have two beta 20s and a beta 250 center(ebay). They have great sound and can produce great volume. I also threw some KEF 2001.2 from craigslist on the back sides i'm very impressed with those speakers. They have a very clear sound and a very high WAF. and it makes a pretty sweet 6.1 system. I plan on adding a Dayton 10 or 12 inch.(depends on WAF) I have a SE-100 receiver I got for about 90 of ebay.
I love the system. I have been listening to cd's and watching movies with a new sense of appreciation.
If you want to go Bose you can get a used system off CL. I prefer infinity and Kef for it's looks and sound. Before you go all out on a new system I suggest you take a look at Ebay, reviews, and do demos. See what you prefer. Everyone's style/preferences are different. Of course I don't think you can go wrong with any recommendation on here. I doubt anyone here has a terrible system.