Any of the following would be cool:
Halo: Warfleet 2
Brigantine, Carrack, DAV, Man O'War, Halo, Unyielding Hierophant, covenant frigates, post war dropships and some UNSC ships.
Armours: Combat harness, Outrider, Ultra, Storm, Commander, Zealot, Devoted Sentries, Infiltrator, Ranger.
Vehicles: Wraith (AA, T26, T58), Ghost (pre and post war), Phantom (T58,T44, T52), Spirit T57, Revenant, Lich, Seraph (H4), Spectre, Banshee (T54, T26B,A,C, Ultra, Temple), Scarab
Bases: Nuff said
Weapons: (pre and post war models) Plasma rifle, carbine, needler, fuel rod gun, assault cannon, plasma cannon, burnblade, plasma swords (including famous ones), grav hammer, beam rifle, needle rifle, blood of suban, storm rifle, plasma repeater, focus rifle, concussion rifle, plasma caster, spiker, mauler, brute shot, plasma grenade
Don't care about the UNSC part. XD
Earth with detailed map, and info on URNA, China, Japan, Deutschland, Korea, Vietnam, Kenya, Australia, Brazil, Russia and India and maybe some cities (Nanjing/Beijing/any major chinese city, Tokyo, Seoul, London, Syndey, Rio de Janeiro, etc. Plus info on the battle of earth and how many died or evauated and how people were returned to earth after the war.
Same stuff as earth for each planet plus a map of each system with planet/star/moon names, types and important locations plus images.