Here is what I would like.
-Sandtrap (for H3 BTB, though a different version to what is already in the game)
-Avalanche (same deal as Sandtrap)
+Maybe one or two more 4 vs 4 Halo 3 maps and one or two more BTB maps
-Hornet (realistically, this would be similar to the Wasp, yet different enough to justify its inclusion as its own vehicle. personally, I'd love to see it back)
-The Elephant (for Sandtrap-not essential, but would be a pretty neat touch)
-M90 Shotgun (It would be nice to see the classic Shotgun show up again, even if, as far as gameplay goes, it only had minor differences to the one already in the game)