It all depends on what your friend wants the car for... Obviously, you are going to get alot more people that are going to favor a Del Sol in a Del Sol forum... everyone on this forum is damned happy to own such an awesome car, and would recomend getting one to anybody.
If your friend wants a good looking, great handling car, with the benefits of a removable targa top, then the Del Sol is definitely the way to go.
If he wants a car to cut apart, and use strictly for drag racing, then the lighter and cheaper CRX would be a better decision.
Both cars are great, and can both be made fast fairly easily... it just depends on what his plans and his budget are.
Good luck.