Any hostel recommendations in Tokyo?

Hi, I am going to stay in Tokyo for 2 nights. For one night I would like to try out a capsule hotel, but for the other I would like to stay in a hostel (low cost and opportunity to meet fellow travellers). There are so many to choose from - does anyone have any favourites?! Thanks!

If you are female your options for capsules will be quite limited.

For Hostels, K's House, J Hoppers and Khoasan are popular ones that get mentioned here pretty often. A friend enjoyed his stay at Ace Inn Shinjuku too. As you mention, plenty of others if you search.

Enjoy your trip!

It's all up to what you're happy with of course, but there are many inexpensive yet clean places. You also might look at:

http://www.wix.com/astroflight/accommodations
http://www.toyoko-inn.com/eng/
http://www.superhoteljapan.com/en/
http://www.newkoyo.com
http://www.juyoh.co.jp
http://www.khaosan-tokyo.com/en/original/

And if you have never stayed in one before, I recommend you spend at least a night in a Japanese Inn or ryokan. There are some inexpensive ones in Tokyo, like the Kimi, the Tama, the Taito and the Tokyo Ryokan. See:
www2.dango.ne.jp/kimi/ryokan.html
www.tamaryokan.com
www.libertyhouse.gr.jp
www.tokyoryokan.com

juyoh and aizuya in are the best

Khaosan Tokyo Original (http://www.khaosan-tokyo.com/en/original/) has a great location by the river in Asakusa. I really enjoyed my stay there last year.
Toco Tokyo Heritage Hostel (http://backpackersjapan.co.jp/english/) is in a newly renovated traditional Japanese building. It's very nice with sliding doors and a garden. The walls are very thin, though, so be prepared that it can be a bit noisy. The location is not the best, but it's not too far from Ueno which is on the Yamanote Line.