Well,as for SA1, go play the Dreamcast version,because its better and doesnt have many repetitive bugs.
SA2 on Gamecube is quite good,especially Chao Garden.
There is only one thing to say: The Gamecube ports have the diffrent names unlike Dreamcast versions.
SA1DX is the Gamecube name for Sonic Adventure 1: Director's Cut.
Same goes for SA2:
SA2B-> Sonic Adventure 2: Battle.
I dont see anyone using this nicknames,so i will use them.