Besides the obvious Starbucks choice[1], my personal recommendation: PieFace. Their cafes are throughout midtown and have good coffee + outlets + seating + great food (Australian meat pies and pastries).
They claim to have wifi but I usually use my phone's hotspot.
1 - for those who want (need) Starbucks, the one at 39th and 8th Avenue has tons of room on the second floor seating area.
Thanks all for the recommendations. I also found the CapitalOne 360 cafe to be pretty nice on the second floor (bonus: TV for world cup games :)). Interest is a bit slow, but the area is nice. I'll check out the other recommendations. I'm also down to meet up, I'll be here until Wednesday (traveling from SF, where I worked at a Startup there)
I'm here right now with a friend at We Work 222 Broadway, Fulton. Seems like a pretty place to work and chill. Spent the day looking for other co-working spaces and narrowed down to this one. Wasn't too keen on doing the coffee shop thing.