Just had the "Brown Sugar Lemonade" from the Clover Food Lab, the food truck parked on Carleton St. right behind MIT Medical (and steps away from the Kendall/MIT T stop). It was fine, but not particularly remarkable. It wasn't too sweet, and had a very subtle tinge from the brown sugar, but the lemonade itself didn't have a strong flavor. They also had honey lemonade and lavender lemonade (the latter sounded even better, but they were all out when I stopped by right at their closing time of 2 PM). I did like the large chunks of ice.
The lemonade at Wrapro in Cambridge also isn't the very best I've ever had, but it does seem to have a tinge of rose water in it, which does add something special. (If only I could get them to add ice!)
Of course, the rosewater lemonade at Baraka Cafe in Central Square Cambridge is as fantastic as its reputation would indicate, and is much more strongly flavored (with rosewater, rose petals, and some other spices).
I hate to heap any praise upon Legal Seafoods, one of my least favorite restaurants, but their Arnold Palmer (half-lemonade/half-iced tea) is one the very best versions I've had. I think because they put it on the menu, someone has tested the proportions carefully, and if one dares to order this most other places what you get is very hit-or-miss.
I must also say that I like the mojito lemonade at Cosi is pretty good, although the mint is not actually muddled, and the whole thing is a tad sweet, but definitely a step up from most lemonades.
Any other interesting lemonades, or truly fresh squeezed lemonades, lurking about?