From the Super Mario Wiki
Pizza is a type of Italian food found on both Earth and Mushroom World. It is a highly-regarded food to both Mario and Luigi, although many other characters appreciate pizza just as much, if not more. Flat and usually round, pizza generally consists of a crust made of dough covered with tomato sauce and cheese, on top of which additional toppings are usually added, such as meats, vegetables, or mushrooms.
 Mario Party 3
Pizza is featured in the Mario Party 3 2-vs-2 minigame Eatsa Pizza. In Eatsa Pizza, the two teams must compete to eat their half of an enormous pizza within thirty seconds. Whichever team either does so, or comes closest, wins the minigame.
 Mario Party 9
The Mario Party 9 minigame Pizza Me, Mario has players racing to decorate a spinning pizza with their own toppings. Players must toss their toppings onto the pizza one piece at a time. Once one player decorates all eight pieces of the pizza with their topping, the game ends and players are ranked based on how many pieces they managed to decorate.
 WarioWare series
Pizza is featured in WarioWare: Twisted!, where Mona is shown to work at a pizza restaurant appropriately entitled Mona Pizza. Despite the name, Mona appears to be little more than a spokesperson for Mona Pizza, which is actually run by her manager, Pizza Joe. Mona Pizza's biggest rival is Pizza Dinosaur, a giant pizza franchise with over 6,000 locations.
Although Mona Pizza never appeared in another game proper, a souvenir simply called "Mona Pizza" could be unlocked in WarioWare: Touched! if the player loaded up the game with a copy of WarioWare: Twisted! in the Nintendo DS's Game Boy Advance slot. Also in the game, a microgame called Wanna Slice? includes a pizza. Additionally, Ashley and Red's microgame Cold Call from WarioWare: Smooth Moves involved answering a telephone via the Wii Remote. Sometimes, a voice on the other line would ask for a Mona Pizza.
 Super Smash Bros. series
 The Super Mario Bros. Super Show!
Pizza was featured prominently on The Super Mario Bros. Super Show!, where it was consumed primarily by Mario and Luigi, especially during the live-action segments. Mario and Luigi's telephone at Mario Brothers Plumbing, dubbed the "pizza phone", was the result of an old pepperoni pizza somehow melting itself to their standard phone prior to the events of the actual series. Although the melted pizza wound up being irremovable, the phone still works properly. In "Fortune Teller", Mario and Luigi went so far as to proclaim themselves pizzatarians, implying that there was little else they were willing to eat.
Pizza was also referenced throughout the animated episodes, although far less often. Instead, pasta appeared to be Mario and Luigi's primary choice of food in them. However, pizza was the focus of the episode "Quest for Pizza", in which Luigi, Princess Toadstool and Toad had to assemble a pizza in the primitive world of Caveman Land in order to revive a petrified Mario. Aside from this instance, pizza played a rather minor role throughout the animated episodes.
 Super Mario World television series