Gulliver's House is a small but very friendly affair, right in the heart of Rome's backpacker area. With only three dorm rooms, it's little more than a large apartment tucked into a building; but both the staff and the people are very friendly, and the lounge/TV room is a great place to hang out and shmooze (or to just watch The Simpsons all night). Sadly, as with all good places in Europe, you do need to book this place ahead — but if you're able to plan exactly when you'll be staying there, it's well worth the effort.
Meininger London, an English branch of a German chain of hostels, is a funny one. Nice location, in South Kensington; and nice rooms, facilities, and all that. But it's a bit weird, as hostels go. Doesn't seem to be much of a backpacker place: I guess the fact that they have a conference centre, and proper hotel rooms as well, contributes to this being the case. Plus, not much of a hangout area anywhere, which is a bit disappointing. Anyway, it's good if you want to stay somewhere nice for a short time, and if you're not too concerned about meeting fellow travellers or not.
St. Christopher's Inn is a great little hostel in the pub-infested centre of Bath. The bottom floor of the place is a regular pub, actually — open to the public every evening, and it gets just as many locals as it goes guests coming for a drink. It's not the greatest value for money (but nothing is in Bath), and it does have a few eccentric little annoyances; but it's good fun, and a nice place to crash for a few nights.
Generator London is an enormous place: with over 800 beds, it's the biggest hostel in Britain. It's also in a great location, and it's very cheap (rock bottom for London prices, at least). However, this comes at a cost. Its enormity combines with its weird punk-industrial decor, to make it feel a bit like a prison. The sheer size of the place attracts homeless people: and security guards actually patrol the inside of the hostel, and randomly ask guests to show their room keys, as proof that they're staying there (such a nice, friendly touch, that is). The bar, dining room, and chill-out rooms are nice; but since most people come here in groups, and since it's just so big, socialising is hard. Basically, the Generator feels like a totally last-resort place to stay in London: I'm not planning on getting stuck here again.
The Chelsea International is one of the most popular backpacker joints in New York City. Located close to the heart of downtown Manhattan, it's the most expensive hostel I've ever stayed at (and really, it's nothing special), although it's about as cheap a place as you can get on this island. The only real bells and whistles that they have here are: a kitchen that all guests are free to use; and a nice grassy area and a set of tables, out in the backyard. Their other services — e.g. Internet, laundry, food, airport pickups — all cost extra. It's not the most amazing hostel I've ever stayed at; but it's got a nice mixed crowd of backpackers, and it's fairly good value for New York.
Aquario Pousada Hostel is probably the most famous and the most popular backpacker's lodging on Ilha Grande. Located about 10 minute's walk from the main town on the island (Abraão), it's close enough to have all the island's conveniences nearby, and yet far enough to also offer a bit of peace and quiet. Not that Aquario is a peaceful or a quiet place, as such — what with its seaside bar serving drinks and pumping out music all night, every night. Aquario's good fun, although the staff are not the most accommodating I've ever come across, and the place is not the greatest value-for-money to be found. Probably better to stay somewhere else, and to just hang out at Aquario in the evenings, to mingle with the gringos and to enjoy the ambiance. Oh yeah, and they have a Jenga set — good fun playing this after a few caipirinhas!
Stone of a Beach is yet another one of those places where you go to party, not to sleep. Not that there's anything wrong with that :P. Situated in the heart of Copacabana, it's rivalled only by the infamous Mellow Yellow as "the place to stay" in Rio. And with its sunny rooftop occupied by a well-stocked bar, a comfy TV room, and a sizzling hot jacuzzi, you couldn't ask for much more, as far as having fun at your hostel goes.
Paudimar is the Brazilian sister to the Hostel Inn on the Argentinean side. While it's not as big or as fancy as its famous sister, it's also part of the HI network, and it's also a nice place to stay. They're a bit far out of town, but their spacious out-of-the-way location gives them room for an enormous garden, a set of hammocks, a nice swimming pool, and camping space. They also have a tour agency on-site, for all your booking needs.
This place is famous as the best place to stay, on either side of Iguazu Falls (Brazilian or Argentinean). It was recommended to me by several people in Buenos Aires — and it's so big and so full of tourists, it seems that I'm not the only one that got a recommendation about it. Everyone in town comes here! And with a BBQ dinner every night, live entertainment in the evenings, free Internet and Wi-Fi, a big well-stocked bar, daily tours to the falls, and a huge swimming pool, why would you go anywhere else? The place is more like a resort than a hostel, really. Considering that it only costs about US$10 a night, it's a ridiculously nice place for a travel-weary backpacker to crash at. Hostel Inn: a part of the Hostelling International network.
My mate Patrick recommended Clan to me, back in Ecuador. It's one of the several big party hostels here in Buenos Aires (a city that is one big party, all night every night), and although the building is a bit of a dump, it's very friendly and it has a lot of character. The upstairs bar is the place to hang out every night, and it also has a ping-pong table and a TV, for keeping yourself entertained during the day. The hostel has free bikes, that you can borrow for riding around the city at any time. They arrange weekly games of fútbol ("soccer"), as well as twice- or thrice-weekly trips to see teams such as the Boca Juniors playing at the big fútbol stadium. They do all-you-can-eat BBQs a few nights a week. And they'll even hire buses to take you to the big discos in town, on Friday and Saturday nights. Just don't expect to get any sleep here, before about 4am each morning.