I often use ahrefs, very nice
This is a great collection of tools at your disposal.
REP added to you OP!
By my experience I rank them like this:
Ahrefs: they got the best cralwers, they maintain the biggest link index of all companies. Pretty nice user interface + content analyze + social media content analyze and more.
Majestic They got the most intelligent algos about metrics, they know how to filter trash links and spam and evaluate you links and domains properly. Also they got a lot nice tools and options.
Linkprofile The best free service of these kind. They show you only fresh links though (something like the past 90 days). They provide some pretty useful tools as well. Never tried their paid versions but the free one is top noth.
Majestic simply sucks
Others Generally they sucks as well
Thanks for this useful share...
Actually none of these tools is free, unfortunately...
I often use ahrefs, it's very useful tool