According to Wikipediea, FireRed and LeafGreen are enhanced remakes of Red and Blue, but support the GBA Wireless Adapter for wireless Poke'mon trading.
I know the later games added an assload of Poke'mon to the roster. I'd like to eventually give one of the DS versions a shot, maybe.
The original games were fun though because they had all sorts of weird glitches, like being able to get 100x an item in your inventory, or the infamous Missing No. Poke'mon
I'm sure these glitches didn't carry over to the remake, as there was a possibility of deleting your save data by using either one of them (although I never encountered such a problem, and did both tricks multiple times).