I hate when people say one loss eliminates our chances for the tournament. The selection is based on a complete body of work, and while a loss at Georgia would definitely hurt our chances, that one loss would not put us out of the tournament. In the same way a win over Wake Forest, the current #1, would not put us in the tournament. Yes, if we lose to Georgia we will have to do more to cover for that loss for us to get in the tourney, but we could still make it. I understand you probably didn't mean that one loss would literally eliminate our tourney chances, but that's just a little pet peeve of mine.
Now to the subject at hand, I think a win at LSU would be a big win for us obviously. Its not a must win, but any road win, especially against LSU who is probably the most experienced team in the SEC, would be a good one. The Georgia game is about as close to a must win as it gets for us in January though just because their RPI is horrendous. More than anything, the RPI hit with that loss would probably be the biggest obstacle for us to get in the tournament.