I don't care about toys and junk, but I do like the certain unique aesthetic brought to the genre through Sentai.
Mostly what attracts me is having a group of characters brought together for one common goal (most of the time) and despite the fact that they often clash with each other and others, they've almost always got the bigger picture in mind. Of course some series do this a lot better than others and tie in the characters to the villains and other characters to the heroes, I think it adds a special level of drama and romanticism that other franchises can't bring to the table in this exact way.
The mecha battles have honestly never appealed to me too much, I don't fast forward through them, but there really isn't anything too exciting there on most occasions. In recent series, Gekiranger was my favorite in terms of mecha usage, but I think it showed off the best of that in the first 10 episodes or so.