Rock is no different than any other type of music in that it will sound better with a reasonably accurate speaker than not. Rock music covers an extremely wide range of genres, but in general you will need a speaker capable of high volumes, low distortion, good bass, easy to drive, not too critical in placement, not sensitive too seating/standing position and is tolerant of overloading. Tonally it should be smooth sounding with a nice projection of the midrange. A little bass bump and slightly rolled off treble is sometimes desirable, so match it in a system with tone controls.
Specifically, the Klipschs mentioned above are a good choice. I was never a big fan of the classic JBL studio monitors, but some people swear by them on rock. I recommend you search out a pair, or better yet two pairs of large Advents. They are widely available and easily upgraded (refoamed and new capcitors). Alternatively, but much harder to find are the EPI "module" designs. Models 201, 202 or 400 are excellent choices.
Specifically, the Klipschs mentioned above are a good choice. I was never a big fan of the classic JBL studio monitors, but some people swear by them on rock. I recommend you search out a pair, or better yet two pairs of large Advents. They are widely available and easily upgraded (refoamed and new capcitors). Alternatively, but much harder to find are the EPI "module" designs. Models 201, 202 or 400 are excellent choices.