TSSM is a royal waste of money.
TSFX I head is pretty good [never been to one, not a fan of their marketing]
Access Education is a lot cheaper than all the rest, and the handouts are also less as useful [powerpoint slides, and mostly useless]. However, I find the lecturers quite good, though the things they cover is very basic, they accompany very awesome explanations that allow you to understand concepts better.
NEAP is a lot more expensive, though I definitely recommend their chemistry lectures. Comprehensive notes, excellent revision material. But to make sure you use it wisely, it's better to attend the first lecture. Their physics, on the other hand, isn't really worth it... (pay a lot less for Access Ed and get basically the same stuff... in power-point form)