The first Rainbow Six game predated Halo by three years (and the announcement of the XBox itself by two years) and though it started as a PC title, it was released for all the consoles of the time, including the Nintendo 64. You could argue that Tom Clancy games paved the way for Halo.
To be fair though, the games have changed in the Post-Halo world dramatically. The original Rainbow Six was actually our main LAN party game because it was so brutal, slow and tactical. We literally split up teams into different parts of the house with whiteboards to map out stuff. It was awesome.
> Halo opened the door for Tom Clancy games,
The first Rainbow Six game predated Halo by three years (and the announcement of the XBox itself by two years) and though it started as a PC title, it was released for all the consoles of the time, including the Nintendo 64. You could argue that Tom Clancy games paved the way for Halo.
http://en.wikipedia.org/wiki/Tom_Clancy%27s_Rainbow_Six_%28v...
http://en.wikipedia.org/wiki/Halo_%28series%29#Original_tril...
http://en.wikipedia.org/wiki/Xbox#History