I am not proud, but I have been addicted to Starbucks for some time, especially double tall lattes. But over time, Starbucks has become more and more the McDonalds of coffee shops. For one, the quality of the lattes varies significantly. I suspect this is a function of a number of variables: the setting of the espresso dispensing machines (both the machine that grinds the espresso and the machine that brews it), how long the milk has been sitting, the temperature of the milk, and the quirks of the barista. Moreover, on those occasions when I wanted just a drip coffee, I've noticed that they've "dumbed down" their coffee selection. More often than not, I find that both their "traditional" and their "light" offerings come from their selection of "Mild" coffees, and rarely from their "Smooth" or "Bold" selection. I would have thought that, since they always offer two selections, that one should be of the mild variety, for those who prefer weaker coffees, and one should be at least smooth, but preferably bold.
The other day I found myself near the Peet's in Wellesley, so I stopped in to sample it. It was awesome. First of all, their small latte (none of this misleading and pretentious "tall," "grande" and "venti" crap) is made with two shots of expresso, so there is no need to pay for an extra shot like at Starbucks. Also, at least when I was there, they steamed the milk to order, instead of steaming a large vat in advance and letting it sit. I find this critically important for two reasons -- first, when Starbucks heats a big vat of milk in advance, they overheat it, because they know it's going to sit for a while before it is used up; second, the taste of the milk changes over time, particularly when it cools and then they reheat it a second time.
So for now on, when I find myself able to choose between the two (e.g., in Newton Center, Wellesley, and Lexington Center), I will now head to Peet's instead of Starbucks.
On a related note, the consistantly best lattes I've ever had are served at a little coffee shop in Lenox Center. I don't remember the name of the place, but I've been there a number of times and have never been disappointed. They also have a funky way of pouring the milk that creates an image of a leaf on top of the steamed milk. It's very cool.