They're actually very similar games. I'd say without a doubt that the Zelda game most similar to WW is TP, and the game most similar to TP is WW. It's no surprise, seeing as they were made for the same system in the same era under the same direction.
My favorite is TP; the cinematography is the best in the series by far, the music is superior, the stakes higher and more immediate, the characters are more desperate, the dungeons are more developed and items more unique, the visuals are more intricate (just look at the vistas throughout Hyrule), and so on. But that's not to say that WW is lacking here; these two games have a lot in common that push them above the rest of the series:
My favorite is TP; the cinematography is the best in the series by far, the music is superior, the stakes higher and more immediate, the characters are more desperate, the dungeons are more developed and items more unique, the visuals are more intricate (just look at the vistas throughout Hyrule), and so on. But that's not to say that WW is lacking here; these two games have a lot in common that push them above the rest of the series:
- Developed Characters-- probably the only two games to properly disect their major characters along a properly developing narrative. MM did this too obviously, but the plot structure was too unconventional to achieve the same effect.
- Similar pacing-- a thorough intro and a whole unraveling dramatic progression all preceding the first dungeon. Then the plot moves quickly into the post-third dungeon plot twist, then an intermediary dungeon (a turning point), 2-3 more dungeons with a more open world, and the conclusion.
- Cast-- OoT allies you with royalty and the Sages. MM with the Four Giants, SS with Impa and Zelda and so on. Always a divine or mystical being. WW turns away from this, and TP scraps it almost entirely. Your allies in these games, with the exception of I suppose your partner, are down to earth, seemingly run of the mill individuals with a remarkable capacity for courage and self-sacrifice. The Pirates, Medli and Komali and Quill, Aryll, Renado, Telma and the Group, Ilia and the Gorons and Ralis, etc. The people who are most directly involved in your quest, whom you care most about and are closest to, are not sages or kings or princesses or ancient warriors who know everything about everything (again with the exception of Midna and the KoRL), but normal people, not locked away in some otherworldly chamber, but out in the field with you, tasting the grit and the blood of hardship and pushing past it for the sake of one another, and that is a remarkably powerful distinction from the other games.
- Tone-- Yeah, this is odd to say looking at the visual differences, but take away the aesthetic and you have two very similar stories, rivaling one another both in scope and in their personal quality, and with similar themes and internal conflicts.
- Eloquence-- these two games are the most confident in storytelling and theme, along with MM probably. Maybe that's subjective. Just a feeling I get.
- Controls-- especially combat. Similar schemes, by far the most nuanced and fluent action in the entire series. I'd say TP probably has a leg up here because of the hidden skills and just the more polished feel.