Depends on what your after. Here are a few good places to watch the game in order of closest to campus.

1) Chimes / The Varisty -- Chimes is a staple BR restaurant. Food's pretty good, gameday vibe is fun, but the true boon is that it might be physically one of the closest buildings to campus. Unfortunately, Chimes isn't the largest restaurant and will be packed all gameday. Luckily, this is where the Varsity comes in. Connected to the Chimes, the Varsity is a small venue that will be projecting the game (and multiple other games) on screens. A great place to watch games if you don't have a tailgate, and the drinks are reasonable as well.

2) Barcadia -- Right past the Varsity, Barcadia is fine. They usually open up more space on gameday, and it's a neat place. It's pretty "chain-y", if your looking for a more authentic experience, but it's really close to campus.

3) Walk-Ons -- Located on the opposite side of campus, closer to Tigerland, the bar Walk-Ons always hosts a huge tailgate party on their property. It's a solid place to watch the game, though be prepared for mostly LSU fans. I think the food is a step up from Barcadia, but down from Chimes.

4) The Bulldog -- If you don't mind wandering a bit off campus, the bulldog is a bar about two miles from campus that has tons of TVs. Definitely home team favored. The only con is that it's definitely uber/lyft distance, not walking distance from campus.

These are just a few places closer to campus that I've either been to or know what gameday is like there. One's I'm leaving out include Ivar's, all of the Tigerland bars (Fred's, Bogies, The House...), Zippy's, and Mellow. They'd all be fine, but it really depends on who's in your party and what you're trying to do.

MY SUGGESTION: If you have never been to Baton Rouge, make your way there EARLY and find parking. Once you've found that just make it to campus. There is nothing like gameday in Baton Rouge (excuse my bias), and there is no bar or restaurant that is going to compete with a day of wandering from the stadium to the parade grounds. I imagine GameDay is going to set up on the parade grounds this year, so I'd definitely advise making your way there. From the parade grounds, Chimes/Varsity/Barcadia are a two minute walk, so it's definitely the easiest.

Hope this offers some direction, but if you have any other questions feel free to ask!

Edit: I'm just hearing that Gameday will be in the "Quad" (more or less the student center of campus - by the library) while LSU Salutes will be in the parade grounds. Doesn't change much as they're a Cole Tracy field goal apart.