My mom has worked in the specialty toy industry for 30+ years and my brothers and I grew up with Brio. She now finds Nuchi the best of all. It is much less expensive than Brio, but made of harder wood than the Ikea, Target and other inexpensive brands. The beauty of the hard wood (made in carefully monitored factories intent upon safety and sound worker conditions) is that it lasts! Beech wood lasted through 3 of us and is not only a keepsake housing our memories, but will live through my children as well. That's real value!
Nuchi is a product of the Little Little Little Toy Company and can be found mostly in locally owned toy stores. The best part of your question, though, is the value of rail play for kids. It's a puzzle that grows and changes as our kids get older. My brothers and I would design a layout and then rip it apart and start over to make it "more twisty" or "longer and skinnier". The train cars were fun, but not nearly as important as the track!
L., mom of a two year old!
PS--a REALLY important thing my family learned was that "less is more". Start with small sets and gradually add a few pieces of track and switches over time. The toy seems brand new with new "puzzle" variables added. How many new layouts could we figure out now? Metered out in this way, kids can play with Nuchi from under two through ten. That's a great "cost per hour" of play ratio!