Walk in to browse, leave with a great suit: Suit Supply
In the last couple of years Suit Supply has come out of nowhere (or, rather, Holland) and made it really, really cool to wear modernly tailored suits with wide lapels. If you need a suit for next week or this weekend, go right to Suit Supply and get ready to walk out with a suit. They've got a wide range of cuts to accommodate any height and figure, and the fabrics and detailing is unheard of at this price point ($400–700). With on-site tailoring and knowledgeable salespeople, you're going to be very happy when you leave.
Off-the-rack, American made: Club Monaco
American-made suits can be hard to find, especially in mid-level men's retail. The Club Monaco brand has undergone a bit of retooling in the last couple of years, and in that time has begun to produce more men's clothing in U.S. factories. A big part of their Made in the USA men's stock is their suiting, which consists of a line of blazers and trousers that are neither too slim nor too boxy, with slim-but-not-narrow lapels and modern cuts. I know nothing of the quality of these, but an American-made off-the-rack men's suit like the ones they sell has a lot going for it on paper.
Suit separates: Epaulet
Epaulet began in a small space on Smith Street in Brooklyn, and has grown a loyal customer base thanks to their line of fastidiously designed and well-made in-house line of shirts, pants, jackets, and outerwear. Their Rivet chinos and Walt trousers are available in an impressive amount of fabrics and colors, and fit great, and the continuous stream of special make-up blazers and suit jackets offer a fantastic way to put together a suit of separates for a great price. There are a couple of paired suiting options, too, in the event you're not into mixing and matching.
The sale suit: LBM 1911
Buying a suit online may seem to defeat the purpose of going out to buy a suit, as the customer experience of getting fitted and your suit tailored is more than half the fun. However, sometimes opportunity knocks and you have to pull the trigger on something great while you've got the chance. LBM 1911 has perfected the art of crafting a suit of fine materials that will look good at a wedding as well as when you want to go to a fancy dinner – you'll be overdressed (another entry in the "good problem" category) but never feel like you are. And just like anything else, if it doesn't fit quite right when you get it, seek out a good tailor (and bring some cookies with you).
USA-made made to measure: Freemans Sporting Club
FSC is relatively new to the made-to-measure and bespoke tailoring arena, but their panache implies otherwise. The thought and care that goes into their suiting is on another level, and that the whole thing is constructed and made in New York is a huge selling point. Not everyone needs a made-to-measure suit, but if you're in the market for one, make sure FSC is on your list.