My nearly-4-year-old has had a wooden train set (brio etc) since he was 2, and we've added to it over the years so he has quite a lot, plus tons of wooden Thomas engines (he really likes/liked Thomas the Tank). I'm reluctant to start off another massive expensive collection, and we've already got some good ideas for presents (he doesn't see many adverts or toys so he doesn't specifically ask for much). I don't want him disappointed though (he has had expectations in the past of getting particular engines and it's horrible to see him wonder why he didn't get them (because we're not mind readers!)) We have Thomas and Percy (and I think you can get James the red engine etc.) Also Bigjigs do replica real engines - we have the Mallard, and a Japanese bullet train, and the Duchess of Hamilton. (Sorry, I'll get me anorak...) I found this article which is useful but has annoyed me at how they keep changing things (and no doubt have changed again since that article)!. craftulate.com/which-thomas-and-friends-train-set/ I think it was my favourite toy when DS was younger, hours of fun (we once reconstructed the roller coaster at our local theme park out of brio and duplo).

Thomas the Train Mini Track - Etsy

www.fisher-price.com/en_GB/brands/thomas/products/My-First-Thomas-and-Friends-Railway-Pals-Thomas-FFY26