E.reg have it all: multiple forms on multiple pages, with multiple types of custom fields, also field groups and verifying system.
Form layout designer with drop-down method (which is an awesome idea!)
The activation re-send and password reset features are also nice, along the email-variables.
It comes in a pack with modules.
We've reported some bugs in the verifying system with custom fields (integers), and in the dropdown form builder.
Also, the CSS class-system could be more deep, for the possibility of detailed customization / "theming".
They dont have a member ticket-system (yet), only forum+email, but we got an issue, and they replied fast and the problem was solved. (thx Hazaa)
Very professional, not flawless, but near to it, totally worth its price.
Recommended and big five!
Keep up the good work, and make it unbeatable! :)