For which socket? For 478, it would be the Swiftech MCX4000. I went against your anti-Swiftech sentiment intentionally because it is the best socket 478 HSF available. For a smidgen less performance but about $15 less is the Alpha PAL8942. Even less expensive is the ThermalRight AX-478 which is slightly less efficient with slower fans than the first two mentioned but depending on the budget, it may not matter. Those are about the only HSFs I would consider as a formidable upgrade over the stock Intel P4 HSF. If using an OEM P4 which doesn't come with the Intel HSF, I would take a look at the Taisol HSFs and the AVC Sunflower which all go for $10-20.
For socket 370/462 (socket A), the best would be the ThermalRight SLK-800. A cool "hack" for this one is that you can situate the fan clip so that you can fit a 92mm fan on their for better performance:noise than that of 80mm fans. It is made of solid copper and goes for around the price of the bare MCX4000. The ThermalRight AX-7 is about half the price, and performs very well compared with the SLK-800 using higher speed fans, but the 100% copper SLK-800 performs better by soaking up the heat more quickly than the AX-7 with slower fans. For all-out bang for the buck performance, the SVC GC68 performs very well with higher speed fans and costs just $6 (bare).