Best: My train table. I've went a step further on the basic train table and have cut more 'themed' wooden platforms to just place on top to switch it up. 1 layer has the train tracks screwed into place (my 1 year-olds kept taking off with the tracks), 1 layer has race car tracks screwed in place, one has a layer of Lego to build onto. I also use the table to put discovery bins on and also cover it with big sheets of paper for colouring, sheets of plastic for painting etc..
Worst: A battery operated ride-on car. What was I thinking? Really bad purchase an indoor playroom...1 day of toes being run over and shins bruised (mostly mine!) was enough.