Dekaranger. I'd tone done on the goofy and play with the cop theme more. I always said, "Less Police Academy, more French Connection." Not just a bat villain, but a whole space yakuza group and I'd tap into the theme of dirty cops. OP theme by Takayuki Miyauchi, not Suckic Lover. And it'd be retitled "Dekaman."
I'd cast Ryou Segawa (Tenma/Sazer Tarius) as Banban. Not the greatest actor, but a VAST improvement over Sainei. Segawa's of a good age and has the look of the hotheaded, loose-cannon type.
Kei Horie (Gao Yellow) as Houji, because he can play the serious guy that speaks Engrish, but is actually cool and needed a better show than Gaoranger.
Jun Takatsuki (Ultraman Neos/Rider Tiger) as Sen, who's no longer the "calm" idiot, but a seemingly by-the-book cop, who's actually dirty. Was an undercover cop who got "lost."
Waka (Faiz's Saeko/Lobster) as Jasmine. She has a mystique. And because she actually looks like she has a thought process, something I think ESPers require.
Ai Maeda (BR2's Shiori). Because you need some young one from a Battle Royale movie, it's like a requirement for tokusatsu nowadays. She has a young look about her, yet she looks like she could crack at any time. Instead of a total idiot, Umeko in my version will just be a new recruit, still appalled by the crimes she witnesses. She had more of a rougher look about her when she had more baby-fat, I think.
Kenji Takechi (JAC actor) as Deka Break, the elite, ultra-cool officer who, against his will and to his chagrin, is transferred to the S.P.D. with Ban and the rest. No break dancin', either.
Hiroshi Miyauchi as Deka Master. No talking dogs in my version!
Sumiko Tanaka (Yellow Four #2) as Swan. Who transforms and does stuff, actually.
VILLAINS
Riki Takeuchi (yakuza flick staple)
Shun Sugata (yakuza flick staple; toku past with ZX and Janperson)
Kenichi Endou (yakuza flick staple; sentai past with Kakuranger)
Yutaka Hirose (Wanda, Kempu, Toranza, Jin) -- I'd have him be the head of a rival yakuza organization.
Youko Amamatsuri (Mazenda, Gara)