Most are pretty inexpensive for what you get and offer one drink coupon per stop. The majority are walking tours where multiple bars are close by, and if you do it early in your vacation trip, you know where to go the rest of the vacation on your nights out.
This is the type of tour where everyone is quiet in the beginning and fast friends by the end. If you are traveling in a group with married and single people this is the perfect night activity since there are usually both married and singles on the tour to mix with. This way the singles will find like minded new "friends" and not feel like the odd man/woman out.
Cannot find what you are looking for? How about make your own. You can always make a theme around your favorite beverages in search of the "perfect drink". Make a plan and theme it around that beverage. Like Tequila? Consider a margarita crawl and sample the tequilas on your adventure. The important thing to remember on this type of themed vacation idea is to stay in the thick of things and don't get stuck in one place too long. Place a time frame on each location and do your best to get everyone to stick with the plan. Make sure your hotel is close by to the bar and restaurant areas so your taxi time is limited or you can walk.
To stay in the theme of your vacation, pack fun emergency hang over kits with caffeine, hot sauce, Tylenol, Mylanta, and other hang over helpers. Collect shot glasses along the way. For the singles groups, pack a pair of “beer goggles” for fun. Many breweries and bottling plants have tours so make sure you put one on your list.
Check out these tour companies:
Pub Crawl Rome
Real London Bus
Pub Crawl New York