Two men fighting. A setup that drives countless fictional stories, and one which Tiger Mask W delivers in spades.
If you are browsing this and ordinarily enjoy a good battle shonen, just go watch Tiger Mask W, you need read no further. Pro wrestling - at least as it's portrayed here - is basically the same thing with more spandex. They still have attacks with cool names and take implausibly large hits, but there are no gruesome deaths or spirit bombs on display, just an occasional "they'll never fight again" killer move to raise the stakes. It's a Toei series, so the quality is typically choppy and relies a lot on "classic" compositions with a static camera against dynamic still poses, but it's well-directed and sustains a feeling of movement for an extended period. Pretty much every fight is easy to follow, flows well, and engrosses the emotions.
OK, you say. The fighting is pretty good. What else is there? The other important part of a series about fighting, of course: giving the characters good reasons to fight. The main plot of Tiger Mask W is a straightforward revenge story, and many of the subplots are roughly as predictable. But like the fighting, it manages to juggle a fairly large cast and develop them at a steady, easy-to-follow pacing. Everything ties together in a neat, by-the-book fashion, which is in keeping with the "throwback" feel of the visuals. You've seen it all before, but rarely with execution this strong. It's not a twisty, meta, or philosophical type of show, it just delivers the goods on satisfying setups and resolution, over and over. Most seasonal anime could stand to learn from this example.
I actually started watching Tiger Mask W with its final episode, which was a chance happy accident: the conclusion to the main plot was in the previous episode, and this was more like an OVA-style epilogue that acts as a teaser for a possible new season or spinoff, with a focus on side characters and stage-setting for new plot arcs. I really hope they go through with producing more of this series, because it's like comfort food to me.