I am just starting out with MOCs, so I went for a reasonable balance of pieces/aesthetics/price on Rebrickable. I went for a 8w Deutsche Bahn Classic: the V 100 Diesel locomotive. They have a great nostalgic aesthetic to them and ReBo Hobby's approach seemed like a good fit. Fully motorised with Power Up, too. The instructions were straight forward and when assembled the model is quite sturdy. Access to the Hub could be easier or at least I would wish an easy way to get to the on button....