I can only go by the ones I've used myself. My Travel System was made by Graco and came from Mothercare. I used it for both my two and it is still in great condition so was definately worth the money (one of the cheaper ones too!

)
As for strollers, I've been through several with the kids what with lots of use, piling too much shopping on the handles etc. The Mothercare ones (around £35) were ok, although I found that as the kids got abit bigger the material started to split at the sides where it fitted around the frame. I had an Argos one which was £30 and the worst thing I ever bought! It was barely even pushable it was so crap and Argos would not refund because it had been used, but I had to use it to find out how crap it was

I ended up buying one second hand from a bootsale which I still use now and it's the best stroller I've had. It's by Fisher Price and it pushes beautifully and concidering it was second hand it is like new, no wear atall.
I know McClarens are good as I borrowed my friend's a couple of times and they seem to last.