Here are the logical Halo spin offs
Halo WRPG much in the way that KotOR did it or perhaps more real time like ME
Halo space shooter... perhaps on a massive scale like that HL2 mod Eternal Silence
Halo CCG much like Ledgends of Norath rather than the way that that eyetoy one sony put out for the PS3

Prequel please !!!!!

survival horror squad based tps with those spartans that were made after MC..the ones with the camo armour ... that have to go investigate some forerunner ruins...they were sent in because there were reports of flood that had taken control of animals on the planet and attacked a human settlement and wiped out everyone and the ruins appear to be point zero because some scientists were running top secret projects on the forerunner tech in the building and found some of the trapped flood

so the spy-spartans are had to go figure what the fuck happened/loot anything valuable/and gtfo before the military neutron bombs the whole planet

and you could have all sorts of animal type floods.

4man squad so you could have up to 4 player co op.

like gears meets l4d meets dead space with SPARTANS! 

i am awesome...microsoft should hire me.

The boxers scream AWESOMENESS!! i want but i think they should not make another FPS halo unless bungie is behind it. IT WILL PHAIL!!! no studio will be as good of crafting a believable story in the halo universe as bungie.

that's a real good idea...

Please bring out Halo 4.

Microsoft is probably creating Halo 4 to launch with the next Xbox.

I believe Halo 4 will launch in 2010. A new Halo game is released once every three years. Halo:CE in 2001, Halo 2 in 2004 and Halo 3 in 2007. Following the three year rule Halo 4 should be announced at E3 and will release before Xmas 2010.

Halo Mario on the way !!!