I like this one better than TS3, but less than TS2.

Great selection of levels/characters/weapons, including probably the best TS level of them all, Planet X.

While it's missing the story of it's sequels, the time trial element is actually really fun once you commit to it, i initially struggled with it growing up, but returning to it i finally got the knack.

At the time of it's release there was nothing quite like it.