>>46699518Depends on what your priorities in these games are.
Crystal has better aesthetics and Johto fans really love some of the little things like the flavor text and less cutscenes but HGSS has a lot more content and Kanto is way better than it was in gen 2. The extra cutscenes might not bother you and the gameplay in general is better.
Aesthetics vs Gameplay is what I put the choice down to, both are good games overall.