I don't have a dream tokusatsu team up.
Well, I do, but it's not really a dream, and it involves non-toku heroes as well. Another story for another day.
I do have some Riders I'd like to see, side by side:
Double Riders and Double
Skullrider, Skullman and Kamen Rider Skull
OOO ShaUTa and Black RX Biorider
Skyrider, Faiz Blaster, Blade Jack and OOO TaJaDoru
Riderman, Super-1 and Birth, if Fouze is as I think he will be, him too
Kamen Rider Amazon & Shin
Kamen Rider Nigo & Den-O
Kamen Rider Agito & G
Kamen Rider Ichigo, Super-1, Kuuga & Decade
Kamen Rider ZX & Decade
Gokaiger & Diend
Kamen Rider V3 & G3
Kamen Rider V3, Aoranger, Big One & Kaiketsu Zvatt with Captain Miura as support.
Kaiketsu Zvatt & Kamen Rider W
Kaiketsu Zvatt & Kamen Rider Skull
Kamen Rider Ryuki, Blade & Decade vs General Shadow
Or any of them individually against him
Colonel Zol, General Wolf & General Monster
Jin Dogma, Crisis Empire & the Greeeds
Kamen Rider Black, Black RX & NEW Den-O
Kamen Rider Stronger, Blade & Kiva
Kamen Rider Black, Agito Shining & OOO RaToraTah
And the upcoming Kamen Rider videogame for DS will make some of these possible.