I don't always buy every game I'm interested in, but if you are looking for a good example it would be Shenmue. I saw some gameplay on youtube, like 2 years ago and found the game really fascinating.

This led me to buy a Dreamcast, Shenmue I and II, as well as some other great games for the system.

A lot of games I like just watching other people play. Other games, I like to play myself, I don't know which fit into which category.

If it's a game that really tickles my fancy, I go out and buy it. When there's a game that's receiving much praise but doesn't interests me, I'll go watch some youtubers playing it.

If it's a game that's not on my platform(s) of choice, then yes. If I'm unsure about the game, then yes. Some games I tend to get bored watching and much rather play though, like the stealth genre (Thief comes to mind).

Some genres I tend to get excited over - be it watching them or playing them. I tend to watch fighters and action games like Ninja Gaiden or DMC if the players are skilled.

There are some games I don't really need to play myself..........DoA Xtreme Beach Volleyball being one of them.......