The Swiftech MCX462 is without a doubt the uncontested best performing heat sink out there. The MC462 follows closely on it's tail, but they are both expensive ($50~ w/o fan). The best deal for your money is the Alpha PAL8045($35~ w/o fan). All three of these HSs use rods and 80mm fans to cool them. Rods equate to more surface area therefore better cooling. I'd go with an Alpha 8045 and a 50CFM 80x25mm Sunon fan. It's very quiet and keeps the 1400mhz tbird in my sig (@1500mhz) running at around 35C.
The air cooled TEC setup I have on my XP1800+ uses a MCX462 and a 68CFM 80x38mm Delta focused flow fan @5000rpm, which is quite noisy but not as bad as the 60mm Delta fans. This awesome HSF combo is powerful enough to cool the 1800+@1800mhz and 1.85vcore plus the heat from an 80 watt peltier module. If you have the cash then it's the best.
Both of these options mount through the motherboard using four spring-loaded bolts. They do not clip onto the socket. You would need to remove your motherboard from the case to install them. For ease, quiet and still very good performance get a Millenium Glaciator II. It clips on to the socket tabs and is an excellent heat sink with a very quiet embedded fan.