Had a quick glance at TCB but their cashback from O2 doesn't seem to be as much as Quidco (unless I just looked at the wrong time, I know how it can change).
Thats the key, the fanboy loyalty in this thread is laughable. I use which ever cashback site offers the best deal for what I'm buying I have no loyalty to Quidco or topcash back it's purely about money!