allthatglitters,
Thermaltake has an excellent line of high performance heatsinks. Not knowing the which processor you have, it is hard to make more than a general recommendation. Some ideas:
If you have a PIII/Celeron (Socket 370 Type) or an Athlon/AthlonXP up to 1800+ then the Volcano 6Cu+ is a good option:
If you have a PIV/Celeron (Socket 487 Type) up to 3.0Ghz or an AthlonXP up to 2600+ then the Volcano 7+ is an option:
If you have an AthlonXP 3400+ or greater, or were thinking of upgrading in the future, then the Silent Boost is an excellent choice:
Take Care,
Richard