when evaluating lead management systems, we considered three:
boberdoo.com
cakemarketing.com
leadmesh.com
Each had its strengths and weakness. Here is my thoughts in a nutshell:
boberdoo - if you already have a front end in place for your own affilaites (directTrack, etc) and want a pure leads management system, they are great choice.
Cake - if you want both the front end piece to manage affiliates, offers, AND the back end piece for lead managment, Cake is great. You can get them both separately, but the power is in the combination.
LeadMesh - Really great for a variety of lead types that work on the ping tree methodology. No real management backend for lead buyers.
Both Boberdoo and Cake are great if you want a lead management system that users can log into, cherry pick, etc. I would recommend getting on the phone with both companies and going through your business to make sure there are not gotchas in how you want to track / sell leads and their systems.