If you really want a good company in building really good and quality backlinks, I would like to recommend this site, I have tested this company and they really give quality backlinks, it is BacklinkTeam.com

Linkamotion is the best linking service

Yea I used to use Linxboss, really juiced up some of my domains.

I've heard good things about backlinkteam.com, it's one of the most popular right now, so there might be something in that.

You should be aware that choosing your SEO or backlinking team is a big decision. It can make or break your online efforts so do your research first.

Getting recommendations on the forum is a good start.

You might also want to contact these companies and ask as many questions as you can about the methods of backlinking, clients successes, report detail, etc. etc, as many things as you can think of that will affect your business.

It is also a good idea to ask for a custom plan or package to specifically suit your competition and get them to actually develop a strategy to outrank your competitors.

Often, the prepackaged plans are not completely tailored to your situation, so this will give you more bang for your buck.

Good luck to you, whoever you go with.

One of the best building services backlink there is Flight Backlink building, they create items for you and send those items all over the internet with 2 links in each article pointing to your site.

One of the best strategies of effective link building service is by building good link popularity for a site, i.e. getting backlinks from good relevant sites having pr more than ours and obl lesser.
One could also opt for free link building service like Voltrank which is really effective and it really works.

i used Linxboss its seems like ok

We have been having good luck with Blastbank