Which processor has the best performance? Pros? Cons?

I'm sorry but you can't just ask that without providing some context: best performance considering cost, best performance in a server environment, best performance in performing x task, etc.

If I were to answer just your question I'd go with Intel; low thermal output which means higher overclocking possibilities, better chip architecture which means higher performance but also higher costs, extremely superior implementation of virtualization technology, better performance in servers due to specific optimization (especially when paired with Intel MBs), better multi-processor support and core logic.

Cons? Price for the most part :)

From what i hear if you don't have much money AMD offers the best performance for the least amount of money, Intel almost always beat them in raw performance with their high end CPUs tough. I suggest you figure out how much money you want to spend and start comparing processors that are in your price range, then you can decide if you wanna go AMD or Intel.

It's kind of unusual for that to be the case. Intel has always been more expensive than AMD, but they're usually not better in terms of thermal output and architecture. Right now you are correct though.

It is worth considering that if the OP wants an integrated graphics chip that he avoid Intel like the plague. They haven't released a decent graphics chip since 2D acceleration was the thing. I've yet to run across a single 3D offering that wasn't significantly worse than the competition. At least with AMD you get a choice of AMD graphics or nVidia. I don't think there's anybody else left in that particular market.

If you mean gaming then it's down to budget......Intel's are the best but the most costly.......AMD Phenom II quad cores are for budget consumers, with models that are good for newer games and even cheaper ones for older gaming only pcs.

Intel offer worse performance-per-cost for desktop CPUs, at the same time they offer graphics, audio, and perhiperal connection solutions that tax the CPU rather than offload it. Their network controllers are good though.

But that's my opinion.

Intel, because macs are using them.

They've been better in terms of architecture starting from the NetBurst implementation (the Pentium Extreme Edition line-up), then took another step forward with the Core microarch. (Intel Core 2) and another huge leap when switched to Nehalem and it's children (i3, i5 and i7 series), and this is only on the consumer side. AMD could never hold a candle to the Xeon line. So this started around 6 years ago.

As for thermal output/processing power ratio I'd like to see a solution from AMD that even comes close to the Atom architecture which will take another leap forward once Cedar Trail hits the market.

Also, the OP only asked about processors so that's what I talked about. Yeah, Intel doesn't give much of a fuck about integrated graphics, and that's been clearly shown in the pre-launch demos of the i7 where they did a lot of graphics work only on the CPU.

Well, the OP didn't really say what exactly he was wanting, so it seemed to be something worth pointing out. IGPs suck in general, but the Intel ones have always been more sucktastic than the competition. Even before that I had one of the i740 cards and while discrete it had terrible performance. Probably because they were trying to use the AGP bus in ways that didn't make any practical sense.