(image courtesy IGN)
Ralph, Lizzie, and George, the monstrous protagonists of the Rampage series, appeared in two different games for the Nintendo 64. The first was based on the arcade Rampage World Tour. The arguably better sequel, Rampage 2: Universal Tour, included new monsters, for the first time in the series: giant-sized versions of a mouse, rhino, and lobster. Smashing buildings and munching on people with your buddies is a good time, no doubt about it.
The first game in the hugely popular tactical FPS series was available on the Nintendo 64. Rainbow Six's trademark realism was quite an innovation at the time. With a friend in tow, you had to plan your attacks carefully, selecting the most appropriate team members in order to maximize chances for success. The level of difficulty and requirement for strategic responses to events made for a very unique, very memorable game. It's no wonder that Rainbow Six would spawn many other games over the past decade and a half.
Though the Nintendo 64 isn't exactly regarded fondly by most modern gamers, it was an excellent gaming system. From a technical perspective, it was the most powerful system available at the time, and the additions of analog control and force feedback would become the standard within a single console generation. There might not have been a huge number of co-op games for the system, but the ones that were available provided great opportunities for teamwork in a variety of ways. The Nintendo 64 is certainly worthy of fond remembrance by fans of co-op gaming.