I fitted a semi slick 225/50/15 Toyo R888, now trying 225/50/15 Yoko A050. Both good. I also used 225/45/15 Toyo but too small diameter and you really do feel every pebble on the road.
Some say 205/60/15 is the best compromise between ride and ...probably dependes on what you use the car for, I fitted mine for the occasional hillclimb.
Terry