A friend of mine has a great magnetic train set ie the carriages have magnets at each end and stick together. She's on hols so i can't ask her where she got it from so was hoping someone on here could recommend something.
Brio or Brio compatible. John Lewis do a good starter kit (loop of track, train, few other bits) for around £20 (can't see it on their website atm). Makes a good starting point. I think Tesco do one too.
You can also get imitation brio at Ikea. It's (just about) compatible with the real stuff. DS has a mixture of both, the brio came as presents from Grandparents and we added to it with the cheapo stuff. He seems a little bored of it now though (he's 2.8), but did play with it constantly a while ago.
Bought a 'Thomas' 'Edward the Great' set manufactured by Learning Curve for my 2.4 month old son 3 weeks ago...it's more pricey than the others but he's a big Thomas fan and Daddy (who bought it for himself really!) was adamant that we get Thomas... DS loves it, so does Daddy, Grandpa, Uncles...DS can now name his trains (we've already added to it-he loves it that much) and refused to go out today 'cos he wants to play with Thomas (most unlike him) I looked at the Tesco one and would have bought that if left to me as much better value. Main thing, make sure theres a bridge, or one in the range to get later...that seems to be favourite bit with big and small! WE LOVE IT!