We've discussed the retail games in this thread before, haven't we? I'm too lazy to flip through previous pages and look.
I have some GBA games, like Cartoon Network Speedway, and the first two EEE games. As far Speedway goes, that was actually pretty fun - I eventually figured out, given that each character racer had strengths and weaknesses, that Red Guy was the best one to race as, because he had the best speed to control ratio; Courage was also a good choice to race as; Johnny Bravo was perhaps the worst, because he had the most weight, so when he caught speed, he was difficult to control.
For the two EEE games, the first one (Jawbreakers!) was incredibly difficult, and honestly, took me months to finish. The second one (Mis Ed-ventures) had much better game play, but the game was also very much easier than Jawbreakers!, so you could probably beat the whole game in a matter of hours.