OK, this is something I do once a year or so--mentioning coffee places on Long Island. The focus of the list is on places where coffee is the center of what the place is about, not on a club that happens to serve coffee along with jazz, or places that are closer to restaurants (where non-coffee items are the main sellers).
The newer places (at least, new to me).
Main Street Coffee in Bay Shore (inside the Drew Patrick Spa, 128 west main street): A relatively minimalist place: a couple of soups, some packaged sandwiches/salads, plus a nice-looking assortment of muffins and cookies (made there? Once source I read says so). The usual assortment of coffee drinks. Competently made espresso, which is an important thing to me. The tables are right near a fountain, and it's proven to be one of the most relaxing places around to have a cup.
Massapequa Perk: on my list for last year, but less than a year and a half old. Made-to-order Sandwiches and salads in addition to the usual stuff, and they've paid attention to the coffee side of things.
Aldo's in Greenport: coffee plus his own biscotti. Half the time I pass the place he isn't open.
Babylon Bean: one of my personal favorite. Beans from Hamptons Coffee; salads and quiches and the like.
Batata Cafe (Northport): used to be Barrister's coffee, IIRC. Drinkable, and I'll leave it at that; focus is less on coffee than it used to be and I probably will be taking it off the list.
Caffe Portofino: in addition to good coffee, they make a surprising number of things in-house, from sandwiches to perhaps the best assortment of baked goods of the bunch. I'm not a big sweets fan, but I really like their "breakfast cookie," which is more like granola than a cookie.
Classy Coffee (Huntington): used to be really bad (horribly over-extracted), but they've improved quite a bit. Haven't been recently enough to say much more.
Coffee Nut Cafe (Long Beach): had some mixed experiences, from OK to pretty good--but none actually bad.
Cool Beanz (St. James): use pod coffee for their shots. Pods (look like round tea bags) can make decent espresso, but never great shots.
D'latte in Greenport: Haven't been there since early fall; I like their affogato.
Georgio's, Huntington: focus totally on the coffee
Milk and Sugar Cafe: Eh. They focus on meals and desserts, not the coffee. Again, it's been a while since I've been there, but the last espresso I had was way over-extracted.
Urban Coffee (Greenlawn): in the middle pack for Long Island.
Witches Brew: cool-looking place and the people are nice, but the worst espresso I've had in recent years.
Places that closed in the last year/two but still may be listed:
The Grind (Bellmore), Brown Dog Coffee (Kings Park), , Sea Cliff Coffee, Java Room (Farmingdale), Pisces Cafe (Babylon). EastEnders in Riverhead is allegedly reopening in May or so, but I haven't heard any updates.
I'm probably forgetting a few; I'll add as they come to me.
249 Main St, Northport, NY
Coffee Nut Cafe
250 E Park Ave, Long Beach, NY 11561
311 Hempstead Tpke Unit B, West Hempstead, NY 11552