There is no favourable visa type that any agent or company looks for.
If you have the right to legally work for the potential employer in the UK for the duration of your employment then they do not care.
It could be Tier 1 general or dependant, a residual Work Permit that you transfer across, dependant WP as well, a 5 yr WP that you apply and secure on your own or a Post Study Worker Visa etc...
All they need is proof of your valid visa to work for them and that's that!!!
Oh and visa worries aside, they are more worried about finding the so called 'perfect' candidate. I know of some employers, who initially say they dont give WPs, but if you are the one they want, they will go out on a limb to make sure you work for them. For most of us, that's a dream come true...
Cheers
KP