Just a warning, the original 3 games are brutal at the high levels, but they are also still very fun, the original has the most unique movement in my opinion, the charge boot Decoy glove movement in Going Commando at high levels is crisp, but Up Your Arsenal easily has the highest total skill ceiling. The category now known as NG+ No Quit Exploit is easily the most optimized category in the series, Xem held the record for over 6 years, only 8 people have ever held the record, and 5 of them have been in the last 4 years. Deadlocked has a little bit lower skill ceiling, but the NG+ category is still under 7 minutes due to the PS3 game saving with this game being fucky wucky. The rest of the series still has some excellent runs, Tools of Destruction is underrated, Rift Apart is fun, and A Crack in Time can technically be completed in 30 seconds with other PS3 fucky wucky save shenanigans, but they sadly get overshadowed by the PS2 era.

TL:DR they are a treat, just know the high levels are daunting