So many choices here. Traditional Metal, Modern Silicone, Pans that let you adjust their size, Pans in every shape from flowers to mickey mouse.

Metal - hardwearing, available in all shapes and sizes. Food can stick so make sure you grease/flour or line them.

Silicone - Easier to clean than metal, but the silicone doesn't conduct heat as well as tin so you can have problems getting brown and crispy cakes. You need to make sure that you put them into the oven in something rigid.

Adjustable - Come in both round and square types, with adjusters that let you change the size of the cake (or in the case of the square ones, cook more than one cake at once)

Shaped and Moulded - Letters, rings, flowers, or even cartoon characters. The ones with a molded base leave impressions on the top of the cake so icing becomes as easy as colouring a colouring book! You'll often find that your local cookware shop will rent out baking tins, since anything large or out of the ordinary can be pretty expensive.