My team has changed quite a bit on Omega Ruby but these are the pokes that I seem to use the most when battling others:
Arcanine
Crobat
Scolipede
Mienshao
Froslass
Absol
I use these guys mostly because they're very aesthetically pleasing to me, I like their typing/moveset, or both. I've EV trained all these pokes plus some others like Espeon, which I might consider using on a team too (though I don't know of a good offensive moveset for it).
I've also thought about using Sylveon since it's such a tank, but I'm not really into competitive battling so prob not.