My brothers got two or three electric trains. I don't remember exactly. They kept asking for them, and then they'd get them, and then two months later they'd be in the closet with an inch of dust, and shortly thereafter regifted.
But those cheapo generic wooden train sets from Ikea, Target, and Kmart? They thought those things were the MOST AWESOME THINGS EVER.
So... know the kid you're getting it for. Some kids love electronic stuff. Other kids love cheap wooden sets with lead tinged paint that they can push around a track and make crash a hundred times over. With enough tracks that they can spend all day building a track long enough that it reaches from the front door to the back door.