Halo 3
This was Bungie's last outing with the series that single handedly started the trend of first-person shooters on consoles that is still going strong today. The first Halo was a launch title for the original Xbox and was an instant hit, helping to establish Microsoft as a legitimate console manufacture. Master Chief's third outing was without a doubt his most anticipated. It saw the game make the jump onto the next generation of consoles, which meant HD visuals, vase online capabilities and further improvements to gameplay. Extensive marketing, internet leaks and some short films ensured that midnight launches around the world were packed with gamers who couldn't wait to shoot some Covenant in the face.
Super Mario Bros. 3
This is the oldest game on our list. Mario 3 was perhaps the first game to get people excited before its release. In those dark times before the internet, it was hard to gauge the excitement that preceded a game, but there were still magazines, friends and marketing to help one get an idea. The first two entries in the series had helped establish Mario as the poster-boy for Nintendo (this is before Sega had thought of creating a blue hedgehog). Helped by marketing such as a feature length film ("The Wizard"), the Mario brothers third outing had gamers itching to try on some new suits to see what they could do.