Banjo-Kazooie Worlds Collide is a fanmade, unofficial Banjo Kazooie romhack. Explore 9 worlds and a hub world, each comprised of memories from Banjo-Kazooie games past, complete with a custom soundtrack made of combinations of BK tunes!
Book of Mario is a text-hack of the Paper Mario (Nintendo 64) created by Fatguy703 and his fans. The text within the game is produced by oscillating translations several times (with Google Translate) to change the dialogue, creating a very different plot from the original game. The game also has a new badge added, which was only obtained via hacking.
Banjo-Kazooie: The Bear Waker is an unofficial Banjo-Kazooie (Nintendo 64) ROM hack/mod. The game features Outset Island, from The Legend of Zelda: The Wind Waker. Banjo and Kazooie need to explore the area and find collectibles while looking for Link, because he is missing and the King of Red Lions is waiting for him.
A mod for Mario Kart 64 which swaps all the racers besides Mario for Link, Zero Suit Samus, Crash Bandicoot, Sonic the Hedgehog, Banjo, Waluigi, and Skull Kid.
Banjo-Kazooie: The Hidden Lair is a passion project by Daveyx0 and Oldum77. It shows a possible continuation of the series, with possible events after Banjo-Tooie. It features a new area of the original Grunty's Lair that acts as the main hub, called the Hidden Lair.
Super Mario and the Cursed Castles is a major ROM hack created by Foxen, having 121 Stars (as of v1.01) to collect spread over 15 courses and a few extra levels. It is notable for two reasons: The lack of any true "secret" levels (all Stars are located in levels that are easy to find), and the sheer size of the game's levels.