Pizza in Brookline?
My assessment of the state of pizza in Brookline is: There is no great pizza in Brookline. There is some fair-to-good pizza in Brookline. Here are my suggestions:
For Greek pizza, I've always found Cafe Nicholas (the one you mentioned, in Washington Square) to be decent, and the Village Pizza House (just outside of Brookline Village, on Washington Street roughly opposite the Public Library) to be, well, a little better than decent. The folks who run it are very friendly. For reasons of convenience (I know, not a chowhoundish virtue), I get slices at Village Fare (a little further down Washington Street, at Cypress Street), mainly because it's next to my laundromat -- they used to have a notable Spinach pizza, but when they changed ownership, the place became brighter and cleaner, but the pizza suffered.
For Italian pizza, well, there's the ubiquitous Bertucci's (there's one within view of the Brookline Village t-stop), which I like, but while the toppings are generally high-quality, they use lots of olive oil, rather than skill and love, to make their crust tender.
Vici, in Coolidge Corner (underneath the Coolidge Corner Theater marquee), is about halfway to an excellent pizza. Their crust is fairly thin, and potentially flavorful, but tough rather than crisp. I suspect that they roll out their crust rather than tossing and stretching it. Their sauce is nicely sweet, maybe a bit *too* sweet, not enough acid. They use decent mozzarella, but they don't cook the pizza long enough for everything to meld nicely -- gobs of cheese slide away as you're eating it. They clearly use good ingredients, but they make less than the sum of their parts. Possibly their ovens are not hot enough, or they simply underbake the pies. ALSO, the service tends to be ridiculously slow for a pizza joint, and the prices are quite high.
On the other side of Coolidge Corner is the Imperial (I think I have that name right), on Harvard Street, which makes perfectly okay, unpretentious pizza, very salty, great if you're hungry and walking by. Don't go out of your way for it.
Best for last -- Pino's pizza in Cleveland Circle, on Beacon Street, next to Eagle's Deli (itself worthy of some chowhoundish review) knows how to make pizza. They are staffed by knowledgeable pizzamen who call you "buddy" and "hon". They do not make great pizza. They do make certifiably *good* pizza -- thin crisp crust, nice sauce-cheese melding, good toppings. They're open late. They are the best of a pretty unremarkable lot.
Foodie alert: Figs in Chestnut Hill (on route 9, opposite the Star Market -- a five minute walk from the Chestnut Hill T, and easy to drive to) makes awesome yuppie pizza. Pricey, though.
Further afield: If you are in Brookline, and you hop on the Green line inbound, stay on until Haymarket, walk into the North End, go half a block up Salem street, you'll hit Ernesto's pizza. Thicker crust than some folks like, but really excellent nonetheless. I'd recommend the Eggplant and the Broccoli-Tomato above all else, but that's personal preference. Be warned -- a "slice" is double-sized -- a quarter of a pie. The prices are higher than when it was Giorgio's (a few years back), and the quality a little less consistent, but it's still very good pizza, and a lot better than most Boston pizza.