Questions like this get asked a lot around here so the search may be your friend.
Ultimately though, I think the answer is..it depends. It depends on what you are looking to do with the property, where you are in your investing career, and a ton of other things.
I like to describe it this way. The LLC is a tool. It has its specific purpose and it has other purposes for which it can be beneficial. It's like a hammer. A hammer is a tool. It has it's specific purpose, banging in nails, and it has other purposes for which it is useful; removing nails, closing a can of paint, etc.
Does that mean when I am going to paint a room I would go buy a hammer? Probably not. While the hammer is a useful tool to have, it wouldn't be needed specifically for my painting job. I can use my rubber mallet, the handle of my screwdriver, or in a pinch I've even been known to just stand on the paint can lid to get it to seal. So no, I wouldn't just get a hammer if I was going to be painting. If I had a hammer (and couldn't find my rubber mallet) I would bring it along, but I wouldn't just get a hammer because I was painting.
Whether you need an LLC is really dependent on what you are looking for and your specific situation.