Even with all that, the big draw is the tour. It's $5, lasts about an hour, and 20 minutes of that is just an open bar of tastings. The tour guides are all great (I've gone on the tour 5 times with 4 different guides). Tickets go on sale at opening, and tours run every 20 minutes (at least on Saturdays). Highly recommend. Definitely a go-to when I have visitors from out of town.
They also have a bunch of festivals at the brewery throughout the year. I've never been, because they're crazy crowded, and the crowd is extremely young (as in average age might be < 23). They have a secondary location in Vermont, but I've never been.
The Beer: Expect most things to be good, but not blow you away. Their IPA is their most popular, available at basically every bar around Boston. The UFO (UnFiltered Offerings) series are quite good (shout out to UFO Razz, one of my favorite fruit beers, and their grapefruit shandy, Big Squeeze), and I tend to like their dark beers more than average. Overall, here are their beers by rating:
That brings the average to 4.35, which is below the site average. Just like Night Shift, that's likely because I've had so many of their beers, and not just their most popular stuff. Of the 3 beers with a rating of '2', 2 of them were available once and never brewed again. They also brew beers that are specifically for different bars in Boston (literally a different beer for each bar), and most of them are bad, which accounts for some of the bad ratings. You can be pretty confident that every beer you get from Harpoon will be good, especially if they actually market it. When you have a brewery this popular, that should be expected.
They also do a great job with variety packs. If you're at a beer store, and can't decide what you want to drink that night, a variety pack from Harpoon is a great way to go. You'll get a few different options, and they'll all be good.
Where To Get It: The two taprooms (at least the Boston one has merch and beer to go also). The IPA is available at basically every bar in Boston, and it's widely available on the East Coast. It's also pretty easy to find in stores, but if you're searching, check out their Beer Finder.