What's the best team in pokemon crystal?

Your team is pretty sound so far. I would recommend getting a few more pokemon to even out the type weaknesses of your team. If you can, find an Electric type. Pikachu would be ideal, but as far as I know, you can't catch him yet. I would suggest heading over to Olivine. In a house near the Lighthouse is a fisher who will trade a Voltorb for a Krabby. Voltorb is a good electric type when trained. For your sixth, find a Grass type. No mater what you do, DO NOT USE A BUG POKEMON!!! Bug Pokemon have the most weaknesses, and their attacks in Crystal are generally weak. Along with that, I would suggest leveling up all of your Pokemon. Since you're on the seventh gym, the Pokemon you'll face will be in the middle to upper thirties. Train your pokemon to lvl 40 and you should be fine.