Waiters/waitresses pushing recommendations on me without me asking for one.

Improper pouring of the wine or wine etiquette. Not that hard, 1- present the bottle to me with label in front of me, 2- remove cork in my presence, 3- let me take a look at the cork, 4-pour, 5-let me try it and 6-I'll nod or say no. It is amazing how many times I see people screw up 2 through 4 (4 they'll either pour too little or too much).