XY OU is one of the better gens for UUs, so I'll just list a few good UU pokes you should consider:
Slowbro: can spread Scald burns or paralysis, walls or cripples top-tier threats like Excadrill, Charizard-X, Keldeo (more of a check though, Hydro Pump can 2HKO), and a few others depending on the set. And Regenerator is awesome.
Amoonguss: a poor man's Mega Venusaur, but it's very stable (again Regen is great), Spore is incredibly useful, and Stun Spore and Clear Smog mess up a host of Pokemon. Very useful for Azumarill, a top-ten OU Pokemon.
Suicune: The CM/RestTalk/Scald mono-attacker is a very tough matchup for many teams that can spread around burns, check powerful Pokemon like Excadrill, Keldeo, and kinda-sorta Landorus, and provide a fantastic win condition against numerous playstyles.
Raikou: A great bird-spam check that can CM sweep or act as a bulky pivot with Assault Vest. (Specs isn't bad either.) It also does really well against genie offense, which is really troublesome.
Celebi: With Aeg gone, it can fulfill its niche as a solid answer to the likes of Keldeo and Landorus much more easily. Those tend to be Pursuit supported though, so Celebi is just okay imo.
Tornadus-T: Great pivot and attacker, though Hurricane is a miss machine without Rain support. speaking of which...
Politoed / Kabutops / Kingdra / Rain: All of these are UU (Drizzle is BL but yolo), and Rain can function well with UU pokes. You may have to get creative with the defensive core though.
Alomomola: Best WishPasser in OU probably, can spread Toxic and burn and generally be a pain to kill.
Mega Aerodactyl: Its pure Speed is problematic for offense and some bulky teams.
Of what you're currently using, Weezing and Lapras are not OU-viable, as has been mentioned. Staraptor is actually a really potent breaker, but I think Scarf wastes its potential a little bit when a CB or LO or something is going to allow it to punch major holes. Most bird-spam checks hate its STAB Normal attacks (Rotom-W, Raikou, Thundurus) or Close Combat (Tyranitar, Heatran). It's a beast.
Why are the beautiful sick and divided like myself?