Bostonians had some quibbles with the TV show Cheers, but no one complained that the concept of a neighborhood bar where the regulars practically lived was implausible. From the Littlest Bar (a closet-size downtown watering hole) to the original Cheers bar (formerly the Bull & Finch), the neighborhood bar occupies a vital niche. It tends to be a fairly insular scene -- as a stranger, don't assume that you'll get a warm welcome. This is one area where you can and probably should judge a book by its cover: If you peek in and see people who look like you and your friends, give it a whirl.

Hotel Bars & Lounges -- Many popular nightspots are associated with hotels and restaurants; those listed here are particularly agreeable, albeit expensive, places to while away an hour or three.

Gay & Lesbian Clubs & Bars -- In addition to the clubs listed on this site, some mainstream clubs schedule a weekly gay night. On Sunday, Avalon plays host to the largest gathering of gay men in town. On Saturday, women congregate at the Ekco Lounge, 41 Essex St., in Chinatown (tel. 617/338-8283). For up-to-date listings, check Bay Windows, the Improper Bostonian, and the monthly Phoenix supplement "One in 10."

Theme a Little Theme -- The Hard Rock Cafe, 131 Clarendon St. (tel. 617/424-ROCK; www.hardrock.com), is a fun link in the fun chain -- just ask the other tourists in line with you. The two-level space boasts a guitar-shaped bar and stained-glass windows that glorify rock stars. You'll see memorabilia of Jimi Hendrix, Elvis Presley, Madonna, local favorites Aerosmith and the Cars, and others. The kid-friendly menu features salads, burgers, and sandwiches, including the legendary "pig sandwich."