Hmm... My favored alts eh? That's a tough one, but I guess I'll list em in order. Homura's a start, back when I made her I didn't have any alts I was really using much. Pretty much just did Tatsu in those days, so I made the young and not so experienced version of Homura as a contrast to my usual style.
Next up would be Kamen Rider Snipe, aka Taiga Hanaya. He's got a bit in common with Tatsu, namely with both using a great number of guns and being pretty used to the whole "Fight to the death" thing. But in contrast to Tatsu who actually likes dealing with this shit and loves a good brawl, Taiga is a bit more sick of the whole thing, not to mention he's a doctor and thus not a huge fan of fights on those grounds too. Also, boat guns are a stupid but fun as hell weapon.
Finally, Taylor Herbert is another fun one. Mostly because she's got an oddball power that's just fun to toy around with honestly, controlling bugs isn't the scariest sounding thing in theory... But well, some of the side-effects in her case make Taylor's usage of that trick quite frighting when she tries. All in all, she's a blast to use because it's enjoyable turning a seemingly "harmless" thing into something dangerous.