R.
Hi. My daughter's love affair with Thomas started around age two and is still pretty strong. We haven't bought much stuff lately, but a really great outing is to go to the "Thomas" store in Oak Brook. We live in La Grange, so it's not too far for us. But if you wanted to take a little trip to the western suburbs, The Learning Curve Store specializes in Thomas. They have a GIANT train table. They also play Thomas videos in the store. On rainy days we just go there to "play". Occasionally, I will buy her a small item (Thomas book or single train), but really she just loves to play and doesn't really bother me about actually buying anything.
Also the DAY OUT WITH THOMAS in Union, IL (I think) is a nice car trip. It happens once per year every August. You can buy tickets online to ride Thomas. You can take pictures with Thomas characters and then just stroll through the railway museum which is a lot of fun for train lovers. Search for it on the internet.
Good luck--
R.