The question itself lacks the information to suggest which lens to get next. If you include what you shoot (Sports, wildlife, etc) it would help, as well as what your current kit is not providing you. For example I shoot a lot of sports, more specifically downhill longboarding, a sport which benefits hugely from a telephoto zoom lens albeit personal style leaves me at the corner with a 20-35L. If you're looking for a fun prime I recommend the 200L 2.8, the IQ and sharpness is superb as well as quick autofocus. Could also add a Samyang/bower/etc UWA to your kit for a cheap, wide, sharp, fast manual focus lens; or a EF10-22/Tokina 11-16 2.8 for a UWA if you plan on sticking with a crop body.