Polenta is a very common dish in every Romanian household but is called Mamaliga. They use eggs and, sheep or goat cheese & sour cream to top it. Another dish they make is called Bulz and its polenta balls stuffed with meats and cheese.

I echo that polenta bars (squares/rectangles are great). Previously, I have topped it with carnitas and avocado crema, a decadent tomato sauce with pork belly confit, but would think it would be cool to do a take on grilled mexican corn (mayo, chili, lime juice and cheese).

for vegetarians, i'm with donny g and a wild mushroom stew
edward espe brown, the tassajara recipe book, has some nice recipes for polenta casseroles if you're interested in exploring in that direction
i've made them, they're good but a little heavy

Make some lamb chops, bolognese sauce and some chunks of Feta cheese.

Porridge style would be delicious, but you'd need to be standing at the stove stirring away, and that's not really any fun. I'd opt for the polenta squares/triangles some other commanders have mentioned. As for toppings, nothing does it for me like a big bowl of burst cherry tomatoes. Put some butter in a on over medium heat, add cherry tomatoes, and allow to sear on one side before shaking pan to turn tomatoes. Every time you turn the pan, a few will burst. After 5-7 minutes, they'll be juicy, soft, and so flavorful. Salt and serve.

Yes, to all of the above. I would do both styles myself. You can make one batch the night before, spread it out on a sheet pan or half sheet pan, cover with clean towels and rest overnight. Cut into serving sizes with a sharp knife, pizza wheel or even a cheese wire and go nuts on the toppings. I'd be thinking about a Tuscan style chicken liver spread myself. Clever idea, the polenta bar.

Oh, I'd do the triangles, or whatever shape strikes your fancy, and then fry them in hot oil to crisp up the outsides. Drain them on paper towels and then keep them warm in the oven. Toppings, all those mentioned sound great, but don't forget the classic shrimp 'n' grits! Shrimp in a mustard cream sauce, or a chili cream sauce, or even in red-eye gravy!

Geez, guys, are you good! We usually do a chili potluck for Halloween--it's cool how many different kinds of chili we get--but now I'm thinking a polenta potluck would be way more fun! Asiago triangles as an appetizer with six crockpots of different toppings, and Indian pudding for dessert. I hope the kin thinks this is as good an idea as I do.

I would do the porridge version if people were sitting at a table, but triangles if you were standing/had plates on laps.

A rich bolognese sauce is classic and always fantastic, but so is a gorgonzola cream sauce.

I would probably make a big batch of caramelized onions with some rosemary in them, and assortment of cheese. I like the idea of doing the polenta both ways. Also what about a sweet option? Some sort of jam or fruit compote?
Can we all come over too?

Just made a polenta casserole from the cookbook Cucina Rustica last night. Basically, it's a layer of polenta, topped with a layer of fresh tomato sauce, topped with a layer of grilled eggplant, then a bechamel, and finally more tomato sauce and parmesan cheese. Then baked in the oven until hot and bubbly. This would work really well and can be done in advance. Plus, it was really good

Well, if your going to have a bar maybe you can serve polenta more than one way. Do poridge and triangles maybe (squares cut in half diagnally). I like to top triangles with asiago and put them under the broiler then put a single leaf of basil in the melted cheese. In addition to David and betteirene's topping suggestions I like to also top polenta with mushroom rague, marinara and a gorgonzola cream sauce. Everyones suggestion here so far would be great!

I'll be posting a recipe for a great topping later this week . . . stay tuned. I'd go with the porridge variety, as it seems that it would be much easier to serve (though others here may have some tricks/good ideas on how to prepare in advance and serve sauteed pieces in this situation). ;o)

Porridge, kept warm in a crock pot, topped with chunks of browned Italian sausage braised with onions, garlic, bell peppers of two or three colors, mushrooms, diced tomatoes with salt, pepper, oregano, with fresh basil added a minute before serving, and garnished with shavings of asiago or romano.

I would do the porridge type and my secret to keeping it from turning into rubber is LOTS and LOTS of butter! I usually have some type of braised meat. Pork butt works really well. mascarpone, garlic braised spinach and or mushrooms, fresh wild arugula, shaved fennel.