I'm a fan of the metcal stuff myself, which can occasionally be found relatively cheaply on ebay. May also be labeled OKi, OK International, and OK Industries. I scored a MFR-1100 power supply with the MFR-H1-SC2 hand piece and several tips for $35 bucks at a moving sale, and it's been awesome to use so far. The tips seem to be robust and have a decent life span, or at least I haven't needed a replacement tip yet nor noticed significant wear. It heats up super fast, fast enough that I can turn it off/on in between solder joints while I check my work and it doesn't cause any appreciable slow-down, and it can dump a bunch of heat into a work piece.
The main downsides are 1) it's not cheap if you don't score a good used deal, 2) the tips operate off some fancy physics where there is a chunk of metal in the tip that only takes energy from the power supply if it's below the temperature the tip is designed to work at. This means that it's pretty good at responding to temperature changes and heats quickly, but you also need to change tips to change temperature. For amps and other stuff I haven't found this to be a problem, I usually can just use one tip (set at 370C I think?) for almost everything, but if you know you'll need to change temperature a bunch of times then it starts getting costly to buy multiple tips.