Tucked in the heart of downtown Littleton, and just three blocks from the Littleton Downtown Light Rail Station, Jake's Brew Bar offers 38 rotating taps, 40+ bombers, bottles, and cans - all Craft Beer! They also have a great coffee bar featuring all local, amazing roasters including Corvus, Method, and Novo Coffee.
You can find their current beer list on Facebook and their website:
Jake's recently expanded to feature a large patio with lots of seating out back. There's also a small patio out front and some indoor seating.
Note that parking can be a little tricky in the area. I recommend parking south of Main, along Alamo Street for the best selection. The side streets between Main and Alamo also tend to have ample availability.