What is Your Favorite Software for Backlinks?

I've never used them, but have heard xrumer, senuke, scrapebox are good.

xrumer is for profile and forum backlinks + others
scrapebox is for blog commenting + others
senuke = multi tier linkbuilding + others

There are a lot of threads and blueprints posted by users who are using this tools. Also there are great tutorials for this tools, here and on youtube. Just search for them

If you are a newbie I recommend you to buy scrapebox with /bhw discount for $57.

xrumer with antispam is king right now.