>> twitter
>> linked in
>> xanga
>> tumbler
>> livejournal
>> hmmm....

>>

It really depends on what you are looking for. Facebook has grown to such a level, you cannot put the rest of famous ones in that category. I think Tsu and Ello are really the ones that might catch up with Facebook's pace.

PS: I don't consider comparing Twitter, Google+ and Pinterest etc to Facebook.

It really depends on what your niche is. My niche is tremendously visual. It used to be that Twitter would send me lots of traffic, but ever since photos came into the picture (pardon the pun), Pinterest has become a heavy hitter for me, followed closely by Google+. For some people it is Instagram, you have to test and see your results.

Instagram is probably the most interactive and liked by millions of people. After that I would say Google Plus. I would take those two sites, for business, before Facebook or Twitter.

I will second what everyone else said prior to me, without question. However social networking sites can pertain to specific terrorities, especially if you're in a niche field. So let's say you create artwork. A novel networking choice would be DeviantArt. On another side, let's say you're an attorney or run a business. You might want to look at sites like Avvo and Yelp (and yes, I do consider Avvo a Social Networking site).

No gamers here? Steam!
Steam community it's huge! It's almost only about gamming, but there's a few design group as well.
Lot's of forum threads, messages, videos, images, you name it!

In my personal opinion it is twitter. I have getting a good number of traffic from twitter.

Tt would probably be Twitter but many problems might be faced using it. Let me make them clear here:

1) The usage of Twitter depends. For example, as in US market it might be pretty useful to target american audience, but if you are targeting Europeans - Facebook would work better as Twitter still doesn't take the top there.
2) Comparing to such a social sites as Facebook, Twitter advertising campaigns will cost you more.
3) Twitter becomes the second social networking site because of its comfortable features pretty similar to Facebook. It could be called as a substitude of Facebook.

after face twitter and linked in both are top social networking sites

If we talk about the popularity in general then it is of course Twitter. However, different purposes means different social networks as well. For example, if you rae concnetrating on professional purposes - then the answer would be Linkedin. If you are looking more for brand building and showing off - Twitter is a great platform. Also, such a networks as Pinterest or Google+ might be useful as well. So the general answer to your question is what is your purpose? then the answer could be more relevant to what you really want to hear.

Top social networking sites:

Facebook, LinkedIn, Twitter, Google Plus, Pinterest

Yes, it's Twitter, but it actually depends on the type of your business. Maybe Google+ would be better, or Pinterest? It really depends on your niche and your target audience.

Google+
Linkedin
Twitter

My suggestion Tumblr and Google+ is best social media sites.

The best and the top social media sites after Facebook
Twitter
Instagram
Linkedin
Pinterest
Tumbler
Reditt
Whatsapp
Snapchat
Wechat
and more if you research in Google you can get more new.

These are the best social media site which are given below and it is a right fit for your business
Facebook
YouTube
Instagram
Pinterest
Twitter
LinkedIn
Reddit
Tumblr
Diggo
Mix
Plurk

No one is correct in this forum, after facebook only Instagram ruling in Social network. If you will check last two year traffic, Instagram ruling.

I think its linkedin and twitter.

I would say LinkedIn because it it microsoft property. If your post does good in LinkedIn then you are going to get a boost on Bing's rankings. You know bing now days gets as much as 20% of all searches done in the web.

After Facebook top Social Media Platform
Instagram
My Space
Pinterest
Linkedin

its Twitter because Twitter has more followers after FB. Instagram, reddit and linkidin also good social platforms

After Facebook, I think Instagram, LinkedIn, Twitter are best but TikTok is also becoming famous nowadays.