@FrankCanada97: Yeah. Initially I had a full unit list on the Red Alert 2 page, but I've since moved that to a guide. I feel like "new units" is something that could stay on a page in the case of real-time strategy games.
In other words, it's very subjective and would probably have to be handled on a case by case basis. In the case of racing games and first person shooters, gun/car/perk/etc. lists should probably stay in a guide.
Personally, I only feel that the soundtrack is an acceptable list, and even that is iffy if the track listing is really long. Metal Gear Solid 4 has a really long list of every song that became available on Snake's iPod or something along those lines.