This area of computer hardware is definatly on the move right now. AMD and Intel keep cutting the prices of existing processors in price war between each other and same time representing new processor architectures.
Still most recommended CPUs for gamers are single-core processors or fast dual core processors. Thats because current games do not support multi-core systems and cant benefit from other cores/processors except in case system is doing several tasks while playing a game. However there is atleast one game that currently support more than one processor and that is patched version of Quake4.
Currently cheapest enthusiast Dual-Core processor on the market is Pentium D 805 2.66GHz sold for about $130-140. Intel processors with Hyper-threading are no longer that interesting cause you can get real dual core for same price (as example Pentium D 820/920 - $180; Pentium D 930 - $300). AMD is going to lower the prices of their dual-core processors in Athlon64 X2 family at the end of July when Intel is expected to represent new processor architecture called Conroe. Conroe is expected to take the crown from Athlon64 and fix some issues from Pentium D - such as the bad idea where two cores had to communicate between each other through chipset northbridge instead directly using separate channel between cores as Athlon64 X2 does. Intel wont built-in the processor the memory controler as Athlon64 does and that wont make difference in speed for now due to still high timming of DDR2 memory modules. For now only old models Athlon64 for socket 939 will benefit from the built-in memory controler using often called DDR1. Dont get surpriced of processor frequencies that Conroe will offer too. They will be equal to Athlon64 cause the processor pipeline is now shorter or with other words it will do more work for less steps.
Single core processors will be mass available with prices of $100-150 and that is a major price drop. Nearly all single core Athlon64 processors already have lower significatly their prices:
K8 AMD64 3000+ Socket 939 $115
K8 AMD64 3000+ Socket 939 BOX $114
K8 AMD64 3200+ Socket 939 $107
K8 AMD64 3200+ Socket 939 BOX $123
K8 AMD64 3500+ Socket 939 $115
K8 AMD64 3700+ Socket 939 1MB $177
K8 AMD64 3800+ Socket 939 512KB $259
Pentium 6xx series featuring Hyper-Threading still cost about the same as before - same as Intel Dual core processors and practically dont worth it.
