I have a 20 mo old boy and we're planning on getting him a train set for Christmas. I'm torn between plastic vs wood railways. Thomas, chugginton,
Lego duplos? What brand do u like? Are most compatible with each other or not. Any suggestions.
I asked this same question on here several years ago, because I was so confused with all the variety of trains on the market!

At the time, our grandson was about a year and a half and was a huge fan of Thomas. He just turned three last month, and is still in love with trains.
I think between our house and his own house, he must have at least one of every type of train available for sale.

He has wood, plastic, metal, motorized, non-motorized, wood track, plastic track. And the funny thing is, he loves them all. He'll go through spells where he plays with the wooden trains, then days where he'll happily set up track and run the motorized ones.
I do think, overall, he plays more with the wooden, magnetic Thomas trains. He has a train table at our house that he really loves, also. It's not the "official" Thomas table, but one that we got at Toys R Us. It was a decent price and came with wooden trains, track and buildings that are all compatible with Thomas trains.
Our grandson also is a huge fan of the Chuggington trains and has about ten of those. They have a slightly narrower wheel base than the Thomas trains and are made of metal. The Chuggington track pieces are plastic and a bit wider than Thomas track. The Chuggington trains don't fit on the wooden or plastic Thomas tracks, but the Thomas trains (wooden, metal, motorized or non-motorized) fit on the Chuggington track. Personally, I think the Chuggington trains are cuter than the Thomas trains!
Then you have the Take n Play versions of Thomas trains. They look just like the wooden railway Thomas trains, only they're slightly smaller and less expensive. Our grandson loves these as well, and has several of the Take n Play train sets (foldable, portable track with attached buildings).
Just a word of caution about the motorized trains. They can drive you crazy sometimes! When our grandson was younger, he used to love to set several of the engines on the floor, turn them on, and let them run amuck. The trains would run into a wall or piece of furniture and just keep clacking.

They can be very loud!
Another poster mentioned the Day Out With Thomas event. We took our grandson last year (he was two and a few months) and he LOVED it! The look on his little face when he first saw the "real" Thomas train chugging toward him was priceless!