I'm currently using Maxxis MoFo XC's. I've read some poor 'reviews' on MTBR about them, but I find them great tires for general XC and downhill riding on loose gravel/roots 'n rocks, and excellent in mud conditions. My last pair were Kenda Koyote's, which were probably the best MTB tire I've ever used. No longer available, I'm afraid.