Comparing CRM from a Customer Support Side

I've been evaluating different CRM systems with the goal of what is the best for Customer Service Management. Here are my findings:

The main systems that stood out are:
Sugar
Salesforce
Zoho CRM
Manage Engine by Advent

I use SalesForce at work but have never been a huge fan of it as I figured there had to be something that is more user friendly but still robust. To sum up my findings...I was sorely mistaken. For the price, features and setup that SalesForce has it is a pretty sweet solution. Sugar and Zoho tied for third. Manage Engine seems really cool but I haven't had enough time to evaluate it but it seems very user friendly and has a lot of the basics needed for support.

Here are some of the main features that I judged the systems on:

Ease of ability to add cases

• Web to Case form creation
• Ability to create cases on the fly without being locked up because the info not being present(Sugar requires the Account to exist before you can create a case for it but at the same time doesn't give you a link to create the account through the Case submission interface)
• Email support - Adding Cases by email and making sure that cases are updated automatically so that there is a history of the development of the case
• Self-Service Portal - Not a huge requirement, but helps in organizing customer info
• Interfacing the Case information with the rest of the CRM: Accounts, Contacts etc
• Ability to setup complex workflow - a lot of the systems have this
• Price point - None are really priced for anyone under 5 users but if you contact them you can usually get a good deal.
  

I'd like to know if there are any OpenSource software out there, besides Sugar, that is good for case management and welcome anyones comments on this. I looked at OS ticket but it seems like it is still a Release Candidate.