First of all, Missing"n"o is a glitch, as u all know. It was never a Pokémon, but a mistake in the game card (hey, not every game was perfect in the 1990's). Missingno actually stands for something if u haven't realized by now. Can u guess? It actually stands for "Missing Number" which is y it's called Missingno.
Back 2 the topic (so this dosen't turn out 2 be a glitch discussion):
my favorite would be crossed with Duskull (n-e-1 that looks like Char Aznable is a friend 2 me, lol!) and Gengar, the cursed laugh is just 2 awesome 2 ignore!