Toy Dream is my 3rd favourite board in MP5 because of all the different things that can happen. It is one of the easiest boards IMO. I like the Toy Soldiers and how they shoot a canon at the number blocks.
It's a basic board like cookiboy17 said. Additionally, it's not very large and it's easy to move around. Riding the train to collect extra coins was really cool, though.
I think that Toy Dream is the most unique board in Mario Party 5 as all of the others are somehow related/ look similar to boards from previous Mario Parties.
Like Undersea Dream is similar to Deep Bloober Sea from MP3 and Rainbow Dream is like Mario's Rainbow Castle from MP1. Toy Dream is one of my favourite boards :-D