Coming from Oregon myself, it's hard not to love the lost leaf. It's like a slice of the northwest in the middle of downtown.
And if your a beer fan, this is the place for you. They have a wide range of many micro's and one of the better places to find beers from Oregon, which of course are far superior then any other beers. No, I'm not biased at all ;)
The crowd is usually a mix between the indie/ art scene and an occasional grouping of theatre goers out after a show. The place is cozy with limited seating, but this does provide easy opportunities to meet others as you all try to huddle around a table for conversation.
The service can be a bit slow, as others have commented as there is usually just a bartender and maybe a bar back who also serves as a busboy, but they have always been super friendly and laid back.
Tip: bring cash if your in a hurry as they take cards, but the credit system is still on dial-up so you could be waiting a couple minutes for the charge to go through.
If you like the Lost Leaf vibe, and want some good light grub, check out Roosevelts as well in the same area.