As KEW already said, if you like the sound, it is (mostly) the speakers that you are liking. As for a receiver, you should primarily think about what features you want, the user interface (controls and onscreen menus) and stick to reliable brands. I personally like Yamaha receivers for home theater, as I like their features and they tend to be very reliable, while generally (in the U.S., anyway) being competitively priced. But a Yamaha does not sound "special" or different from any other competently designed receiver with settings adjusted the same (many people, though, do not properly compare things, and so they can fool themselves into thinking the thing is essentially different, when it is just a feature setting that is different).
Now, if you were dealing with difficult to drive speakers (e.g., low impedance, etc.), then you would need to concern yourself with the amplification. But in that case, you would probably want to buy a receiver with preamp outputs for all channels, and use one or more separate power amplifiers, rather than trying to get a receiver that is up to the task, which, with really difficult speakers, will likely be impossible.
Also as KEW has already said, it is common for people to overspend on electronics. You should put the majority of your money where it will make the most difference, and that is in the speakers. I used to use a receiver that retailed for about $600 with speakers that retail for over $6000, but I replaced the receiver with one that retails for about $1700 because I wanted more (and newer) features. It sounds the same as before, as long as I do not engage a feature that affects the sound. The new receiver is capable of putting out about twice the power of the old one, but my speakers are an easy 8 ohms of normal efficiency, so the old one could drive them to levels I found painful, so the extra power is irrelevant in my case.
In other words, if I were wanting better sound and nothing else, then I would have totally wasted my money on the "better" receiver. If I had spent full retail price, that $1100 extra for the receiver would not buy me any better sound. It is something to think about when deciding how to allocate your money on a system.
Aside from the fact that the sound will be most affected by the speakers and therefore you will get the best sound putting your money there, another great advantage to spending your money on your speakers is that you will not need to replace them when they come out with some new feature that you want. Many people replaced receivers due to the newer audio formats on BD, but there is no need to change speakers because of some new audio format. I personally do not plan on ever upgrading my speakers at this point, as it would be very expensive to get better sound, and it would not be possible to get very dramatically better sound at any price. But I expect that, eventually, I will replace my receiver due to wanting some feature or other that was not available when it was made.
For most people, I would recommend aiming for the bottom of Yamaha's Aventage line, as the quality is a bit better than their lower models, and the feature set is pretty good at that point. But you can go with other brands of receivers and it can sound just as good.
And don't bother with magic wires and other such things, that no one has demonstrated the ability to hear under proper testing conditions (i.e., double blind, etc.). Even if it made some subtle difference that was somehow magically not detectable scientifically (which is a silly idea, but let us assume it for the sake of the discussion), it makes a lot more sense to spend your money on things that make a big enough difference to be detectable with proper testing, and so you should still be putting your money into your speakers. (Subwoofers, by the way, are speakers, too.)
