Which is your prefered admin panel from a reseller point of view?
My favourite is Cpanel, I think partly because it's the one I've the most experience with.
However, I also think it's the consumer's choice, so doubly important to provide it.
Though I quite like Plesk since they upgraded to a Windows interface, little things about it annoy me - such as having to allow PHP on rather than being active by default.
Ensim has a secure reputation, but I find it slow and cumbersome to you. Really, there's no excuse to sell software that uses tables in 2006.
Not much experience with H-Sphere, but again, annoying things such as having to activate PHP, plus it's attempt to fully integrate with everything and therefore potentially over-complicate issues, create concerns.
I don't think I've ever used Windows hosting, so no experience with Helm.
What's your personal favourite, as a webhost or a webhosting customer - and why did you reach that conclusion?