7-11
7-11 is a popular worldwide convenience store, especially in Asia. There are 2 main 7-11's in the Burgos St area and another 2 not so far away. You can get cold drinks, coffee and every other essential you could wish for.
The other really cool thing about the 7-11's in the Philippines is that they have very nice, very cheap hot food snacks such as hot dogs, fried chicken etc. One of the cheaper places to eat if you're on a budget.