mentioned shrimp, I'll just go with it.
I like these meatballs very much (link below). And even though it says to do it in a crock pot, it can be done in 15-20 minutes in a pan on the stove top. Just as long as the meatballs are heated through and the sauce is bubbly hot. Of course, you'd have to stir once in a while to keep it from sticking on the bottom of the pan. And then put them in a crock pot anyway to keep them warm, so that's just messing up an additional pan. Just thought I'd mention it.
Then also, there are tortilla roll-ups, celery-stuffed pimento cheese, spring rolls, a relish tray assortment of olives, ripe olives, dill pickle spears, sweet gherkins, pickled okra, pickled beets, cocktail onions, giardiniera, etc.
I very much like GG's Crabbies, GG's stuffed mushrooms (you mentioned mushrooms), Knorr Spinach Dip (that was mentioned here in the last couple of weeks), and, well, I guess I don't have a Favorite!
What you already mentioned sounds good to me! If you serve too many appetizer goodies, you might have a lot of the Meal left over! I love appetizers!