hmm some interesting opinions flying around here... some I agree with some I don't
I DEFINITELY agree that you should NEVER EVER buy an amp/dvd combo... you might as well try to get your system out of a cracker jack box. The general rule of thumb is the more segregated the system the more professional it is. Systems that run in the $100K range use separate decoders and individual amps for each channel, sometimes even external cross overs and amplification after the crossovers... systems on the clearance rack at WallMart are combo units...
I would also advise against wireless speakers... There are LOTS of cable options that would make the wires completely invisible. Baseboard heaters typically have a small lip on the bottom that you can run wires under and out of view. Monster has a great line of FLAT speaker wires that can be run under carpet without any noticeable bumps. The most professional install would be to go to home depot and buy some speaker wire wall receptacles and run nice thick wires through your walls. If you want to spend a little more you can even get some decent wall speakers that build right into your walls themselves for the best WAF (Wife Acceptance Factor). For regular speakers you can get decent speaker stands that allow you to run the wires up inside the stand. Good quality floor standing speakers will have the hookups on the bottom so you could even run the wires up through the floor.
IMO wireless speakers are over priced, under powered and generally sound like total ass for the amount of money they cost. The biggest problem is that they're usually battery operated and use internal amplification. Any amplifier that runs on batteries and fits in a 4x6 box with the speaker is going to have the audio quality of a cheap radio... because that's basically what it is. and because all the money was spent on the internal amplification they usually cheap out on the speaker itself. That's not to say they don't make good sounding wireless speakers, because they do, you'll just pay 2 to 3 times as more for them.
I also agree on the point about buying all the speakers from the same brand... I'd even go as far as to suggest the same LINE of the same brand. All of my speakers are Cambridge Soundworks for this reason. Because they're all from the same brand they all use similar parts and they all have similar tonalities. I started building my set when they were on the edge of phasing out the "Classic" series for the "Newton" series. Because of this I was able to get my fronts and sub much cheaper then MSRP... Also because of this by the time I went to add the rears I couldn't find them anyway and had to get CS Newton series speakers. Thankfully they were matched close enough to the fronts that it still matched tonally.
I'd have to disagree somewhat on the Speakers over receiver idea mentioned.... while it's true that a quality set of speaker will last a long time... (day I say a decade, at least). I think that for quality a solid amplifier is the key. A good amp can make so-so speakers sound fantastic... however the most amazing speakers in the world will always be limited by an underpowered amp. It's true that Amps/Receivers wont last you as long but IMO they're far more important in the quality equation.
If you're looking to piece build a system the first thing you have to do is determine your goals... How big is your room, how is your room arranged, what kind of content will you typically use your system for? (movies and games, or music ?) What devices do you plan on hooking up to it... Classic Game consoles? (you'll want Dolby Pro Logic IIx support) Modern Game consoles? (you'll want an optical port with Dolby Digital support)Next Gen DVD players? (you'll want Dolby Digital ES and DTS EX support) SACD/DVD-A players? (you'll want 6 or 7 channel analog pre-amp inputs) etc.
Once you have those questions answered RESEARCH RESEARCH RESEARCH... hit up some AV forums (no this one doesn't count) see what other people are using and why, pick up some AV magazines and read reviews.
Once you've got that underway go shopping... And when I say shopping I mean NOT at big box stores... a good rule of thumb is if the store doesn't have a listening room avoid it like the plague. Most Bestbuys/Circuit Citys are only concerned with moving products, they could care less about the buyers post-purchase experience. I wouldn't buy from them unless you had a very specific model speaker or receiver in mind that you KNEW you wanted to buy and they had it cheaper or were closer then any other store.
Part of the reason I went cambridge soundworks was because there was a cambridge soundworks store near me. I read lots of reviews and there were a few brands/model lines that were in my price range and looked good but CS were one of only ones I had an opportunity to listen to in a professionally set up environment. There were a few others but after listening to them first hand I was sold on them.
Tweeter is probably the only big box store that has decent listening environments. I would imagine some of the larger CCs or BBs might but when "shopping" around you're better off doing it somewhere where the staff knows what they're talking about. Local mom and pop shops are often quite good for this stuff too...
Another thing about the AV forums... is you might find people in your area that will let you go listen to their setups. Also lots of small AV start up companies will send around demo equipment for people to try out, they usually setup the demo recipients through these forums so see if one is stopping by in your area.
Don't discredit no-name speaker makers. Some of the best quality stuff can come from some guy in his basement. I have a friend who enters speaker making competitions all the time. he's made a few sets that cost him less then $100 that rival mine

If you're interested in speaker building pick up a parts-express catalog from their website. Each catalog includes a DIY speaker project with detailed instructions and a parts list. VERY cool stuff if you have the tools and the ambition.
on that same note... never buy speakers from guys in vans, especially white vans.
Amps and Receivers are a different boat all together. IMO you're better off going with a quality name brand. I personally prefer Marantz. My father had a Marantz receiver and it sounded amazing, when I got mine I shopped around and found a nice one cheap ($800 receiver marked down to $500) it's been going strong for about 4 years now and I love it. Big Box stores DO often carry decent ones but you'd be better off doing your research else where and again only using the big box once you know EXACTLY what you want. RMS is the only TRUE power raiting, if you can't find the RMS power output for an amp don't bother buying it because it's probably Junk.
.... I could keep going but I think this is a good place to stop for now.

Oh and I'm Pinning this topic... this is just too good a discussion to not be pinned
