We became aware of Lounge Leo several years ago, and even though we don't live in Little Italy anymore we still make a point to stop in every few months.
The bar itself is small and a little hipster-esque, but the atmosphere is comfortable and fun. When you first enter there is a narrow bar space with a few high top tables as you would expect from your regular local bar, along with a snazzy digital jukebox to cater to everyone's musical moods. If you walk straight back through that space and down some stairs you'll find a more plush seating area with some white couches and chairs that are great for medium sized groups to just hang out in.
The bar itself doesn't serve food, but because this is little Italy there are a bunch of great local restaurants within walking distance that you can hit up to satisfy your late night munchies.
All in all we love this place. Mike is our favorite bartender, he always takes great care of us!