re: Boston hotels for long weekend

As you said, area isn't as crucial because the city is so walkable. That said, it really depends on your budget.

But without knowing your budget, here are some hotels that are perfectly situated to check out:

Four Seasons
Ritz Carlton
Park Plaza
Omni Parker
The W
The Ames Hotel

Of course, the top two are the most expensive, but they are also the best located (the Omni is right next to the Ritz and would be much cheaper).

Favorite areas of the city to look for hotels would also depend on what you're looking to do. If the catching a Sox game is most important, then Fenway. But in general, I'd say to look in the Back Bay, Beacon Hill, Theater District, or North End. In that order.