It is simple and relies on your budget!
If you have $200 or more to spend you go Intel, and it is WORTH the premium.
If you have under $200 to spend on a CPU then you go AMD. You will have the best upgrade paths and price/performance *when budget is under $200 for CPU* with AM3 CPU/mobos.
Anything quad core i5 and i7 are superior to anything AMD, and is worth the money for the performance increase (unless you aren't doing anything CPU intensive, which would make it overkill). As for gaming the i5 and i7 will give you the same gaming performance as AMD on most graphics card setups today, but they will carry you into the future into newer and more powerful graphics cards. Pretty much they are overkill for now, so they will provide good future-ability.
So... is AMD good? Yes, AMD is awesome.
Is Intel's performance worth the price premium? Yes, very much so, unless it is obviously overkill for you and you will never need its uber powah!