I dunno; I full-completed
Tomb Raider: Legend, loved every minute of it, didn't even get bent out of shape on the motorcycle sequences. The game just clicked with me.
Tomb Raider: Anniversary didn't work as well for me for some reason. The new control scheme definitely made the whole game less of a frustration-fest than I remember the original to have been, but somewhere during
so-and-so's Folly, I meandered to other games and have not been able to convince myself to go back.
This has also kept me from getting into
Underworld, as the consensus seems to be "same as Legend, but better animation and a frustrating camera," which means it's more fun to watch and less fun to play.

I should clarify that appeal of it vs Anniversary is different. Underworld is a much snappier game with better pacing. Where Anniversary has a single puzzle and platforming section that drags on for a while, Underworld doesn't have that problem. I prefer what Underworld does and I feel like I can play it for longer stretches, but I could see someone preferring the more detailed and longer sections of anniversary. I will admit that the satisfaction for completing those is great even if I feel fatigued by the end and don't want to continue right away. (snip)
This is exactly what killed me on Anniversary: sending me out to individual puzzles so I can bang my head on something for an hour, grok it, bring the key back to the main room, lather, rinse, repeat.

If Underworld is "snappier" it might give me enough momentum to not only finish it, but then roll through Anniversary just to get it out of the way...