Well, I would say the 2000 Si, but that's only because I own one and its extensively built, so I will walk any Integra that comes my way.But, way back when my Si Coupe was still stock, a friend of mine had a 97 GS-R and he could usually beat me by just about one car length. Both cars are great and about equal. The GS-R has a little more torque though because of its B18C1 and the Si is lighter than the GS-R by about 65 lbs but the B16A2 is notoriously bad for torque.Either way you can't go wrong because they are both Honda's!