The brush I use most often is the hard slicker brush. I also keep a pin-brush (like a human hairbrush) for his tail, an undercoat rake that I thought would be a good idea but I never use, a mat-breaker that does get used, and a flea comb. He's never had fleas but the flea comb is very useful to get small debris or tag-along seeds out of his coat. If you have a breed that sheds, you may want something like a furminator or de-shedding comb.