The LS is fun to drive. My car is old as **** (211,000 miles) and all I have is lowering springs, 16" rims, and intake and I frequently surprise myself at how fun my car is to throw around and stomp on the gas! Wouldn't mind having a GS-R but I don't regret getting an LS at all. You GS-R guys are just trying to justify paying more, like StyleTeg said, and I can understand that. A lot of that depends on how much money you make and how much of that money you will put into your car.
I wouldn't say that 28 hp is gonna make the decision for you. The 98 also comes with nicer (in my opinion) headlights, taillights, bumpers and wheels. Not to mention it's 2 years newer which has a certain value.
Ben