I have to post to stop you from making a mistake. You sound like an educated buyer, someone that wouldn't be happy with a package deal, especially anything from best buy. I have to stand up for the piece by peice system, and here's exactly what I'd do.
Receiver: Onkyo 787TX - THX Select Certified, has 6 camps built in and all you need is 6 speakers for THX surround EX. You can get one of these for $599 from Onecall.com and if you want I can get you another $50 by way of a coupon. Otherwise you can get the Pioneer Elite VSX35-TX (same machine without the extra rear amp) for around $500 from http://www.ubid.com
every so many days. I wouldn't bid over $439-459 because that seems to be the going rate (high shipping though).
Anyhow, those two receivers would be fantastic in a beginning system. VERY VERY nice.
As for speakers there's only one manufacturer on my mind when in comes to affordable and great sound. Paradigm. They mostly sell only through individual dealers but it's well worth it. Easily the best speakers for the money on the market. I personally own a pair of VonSchweikert VR-3's but they're not really in the same league as the Paradigm's, much different style speakers. Mine are more for Music than movies. A fantastic Paradigm system can be had for less than $2000 with towers and sub, or less than $1500 for just a great system. I would definitely keep it in the Monitor series at least. The performance series can make great surrounds, but if you're ever going to listen to music get the larger fronts (mini-monitors/monitor 7's). If you just want something that will get the job done nicely and that's about it go with the Energy Take 5 system. It's been on the market for some time now and you can get the 5 speaker setup for less than $500. Good deal, not as nice as paradigm, but decent.
There's thousands of options here, I can't emphasize enough how much you should refrain from just buying a box system and letting that be that. To be the Audio is 70% of the movie, spend you douhg like it is. A friend of mine has a 36" Wega and it's nice and all but I prefer to watch DVD's on my little 31" GE POS with my system over his setup anyday. Once you start listening to systems out there you might start seeing what I'm saying. Anyhow, if you want more advice e-mail me. I'm always checking out classifieds/auctions for good deals, let me know what you're looking for and I can find it. I got my Denon 3801 receiver for less than $700 brand new (retail $1200).
More than anything though have fun with it. It shouldn't be a task to have to chose speakers it should be fun. Take DVD's/CD's you're familiar with with you when you demo and always say NO the first time listening. Without optins we'd all be living with Bose and that'd be one depressing world.