Hazel Kent
Google
5 stars for my purposes.
Pros:
If you're young, flexible and social, this is a really good environment. The hostel's personality was very open and social-- everyone was pretty chatty, people don't really lock doors, and many go out together every night. It was really easy to find people to do stuff with, which was nice as a solo traveller. Everyone respected quiet hours too, ironically diff from less social/ friendly hostels I've been to.
The hostel is colorful and cute. So long as they had beds, fridges, and hot water for their shower, I'm good, which they did, and otherwise have a low price.
Cons:
A little too far from the metro for those with luggage (30 mins thru busy city) and the busses aren't incredibly reliable. Can be tiring to go out.
Not a luxurious stay (see price!)-- the kitchen is small, the showers are small, the mattress is thin. There is no AC which was fine in May with the fans on and windows open.
Worked great for me as I wasn't in Athens long, wanted to make friends and didn't have much $. Thanks everyone!