My family received a big, metal, Lionel train set when my siblings and I were young. I understand they are classics, too, but for us the setup was too intimidating. It may be a good choice if you have an existing enthusiast in the family. My husband’s uncle, on the other hand, had a brilliant idea maybe two decades ago: He began buying their family Brio train sets and additions every Christmas. Their collection is truly impressive by now, and even though all his siblings are in their twenties they still will congregate in the basement and reconfigure the set for hours together, both the men and the women. My husband has years of happy memories of alone and family play because of his uncle’s excellent idea.
Brio train sets are super popular and I can see the appeal. They are simple but very fun to play with. Brio sets aren't the cheapest to buy but the quality is usually there. Argos have at LEAST 50% off Brio Train Sets just now, meaning you can pick up and absolute bargain. They are all selling quick though, so get in there fast.