Some of the issues i have noticed while playing on the Xbox.

-The guns can sometimes change there angle/position while walking.
-The DLC bonus content from Game stop, The Weathered 10mm pistol when mods are used on it, the gun disappears and in first person mode your screen becomes very bright because of the ! box.
-Some surfaces, mountains, floors have overlapping textures and can cause it to flash when you look at it.
-The scorpions in the hidden valley can sometimes go through the ground and there body segments can stretch and look very weird.
-Sometimes when you exit a bunker in the hidden valley the sandstorm can freeze, where the effect is there but its not moving.
-When climbing a mountain or falling down one you can sometimes get stuck inside the rock, where you cant move or fast-travel(it says your falling).
-Sometimes when walking slightly over the hill near one of the NCR camp's the water does not appear in the lake.
-Some of the rocks or structures do not completely touch the ground and you can see through the bottom of them.
-Occasionally while using V.A.T.S the game may freeze and you cannot back out of V.A.T.S and the Guide button also will not work.
-While going to one of the locations when there is a green tint on your screen, The pip-boy's screen will not be affected by the effect and looks dark and normal while the rest looks faded and green.

Those are some of the ones i could remember, hope it helps.