I mostly want more ghosts, more dragons, and even more water-types. You can never have too many water-types <3
For ghosts, I like the ghost/steel haunted suit of armor someone suggested. That would be
badass. I can't really think of anything else right now, though. Nintendo has made quite a few ghost-types by now.
As for dragons, a poison/dragon would be epic, as would a non-legendary fire/dragon. :3
I have so many ideas for water-types, I can hardly name them all. xD a water/dark
anglerfish (I'm sorry, lanturn is too happy-looking to be a proper anglerfish imo :C ), some kind of giant squid/octopus (the latter as an octillery evolution), a water/psychic dolphin, some
plesiosaurus-like thing possibly as an evo/pre-evo for Lapras, some kind of water-type domesticated dog (like a Labrador retriever or something?) Pokémon, a lionfish that's either water/poison or water/electric (the latter just because someone on another forum made this really cool water/electric lionfish-like fakemon)...I could go on and on, really.
One more thing, I really really want a
smilodon Pokémon for a fossil. Probably ice/fighting or something.
Some decent poison-types would be nice, too.