we used AMD and switched and recommend Intel more and more - it seems that AMD is always playing catch up -
also we found more servers with AMD had issues then intel - now we are purely a Dell house so it might be related to Dell

I assume that the choice should be made according to the actual needs of configuration. I like AMD servers more. But that is mine

I'd go with the Xeon.

It depends on what application you are going to run on a server. I would prefer Intel for complicated threading applications and AMD for gaming sites.

In my experience also the Opteron series performs well than Xeon or other nearest intel processors, in the general websites case,

I had never used this for websites using strong data base or need more frequent processor usage like big forums etc.

In many persons view AMD is still searching a place in the server segment unlike Intel processors.

Low End AMD processors are not performing well in server segment but third generation Opteron are doing good in mailing, hosting, etc

If you are not hosting this in-house why do you care about the power consumption of either? Go with the Xeon.

I've got Intel and AMD based servers (owned). While the Intels can be a bit faster, I've paid more for them. Even sticking with the Opteron lines, I paid less than half on a 8 way box than a somewhat similar Xeon with only months between the 2 purchases.

I prefer the Xeon boxes but it's hard to justify the price difference.

There are some companies who offer cheap Xeon servers also but before going to buy please read the processor description in intel site, most of the xeon processor are like remake film of old processors