Which method if applied properly gives the best results. There are so many that one could apply like link baiting, forum sigs, blogposts, buying links...

But do they really work anymore. People are now getting more and more conversed with all this tricks. We need something new to work better for us.

Blog posting , Link baiting and forum sigs still works...and directory submission also...

The most common ways of getting backlinks are thru social bookmarking, directory submissions, submitting to press release sites, forum sigs, link baits, etc. etc.. What's important from an SEO point of view is getting relevant and quality (organic / natural) back links. You get this if you provide very good content that would make other sites want to link to your site. Also having back links to high PR sites helps your site on PR building as well.

On a marketing perspective IMO, having more targetted link backs is very important as these yields the highest conversion rate. In general, the more link backs you have - the more exposure your site gets - the more chances you get traffic from these back links

__________________
The #1 Marketplace for Webmasters | Web Design

In my point of view,Link building is a program of seeking out and building up the link popularity of a site from other relevant and authority sites. It also includes finding relevant sites to offer as a resource to visitors to your site.

I think social bookmarking is the best solution. People see your site, a lot of them, most of them are blog owners, maybe owners of some big sites, they will find out about your site, and they will link to it if you do a really good job. Like that others will 'work' for you and you won't have to waste money on buying links etc.

link baiting, forum sigs, blogposts, all these ideas help us to gain more quality link for our sites since they are one way links considered as natural link by google. also its very simple and quicker way to do.

__________________
SEO, Sales & Marketing strategy

For purely SEO benefits - unique and useful content that is relevant in your niche

Once other sites sees the value in your content and link naturally to your site, thats when you get the quality links that are favored in SEO.

__________________
The #1 Marketplace for Webmasters | Web Design

Thats the theory, but in practics I think 'natural' backlinks depend very much on the type of site rather than the quality of it. So some of us will always have to rely on directories and forum signatures...

__________________
Cool guitar stuff from Mars Guitars in UK
Guitar String Guide

Directories and forum sigs are good sources of backlinks. They help in SERP but less value in PR.

What is link baiting?