Okay, the very easiest guitar tunes we can recommend, categorised by music style!
CLASSIC ROCK
Smoke on the Water(intro/main riff is easiest) - Deep Purple
Tab - http://tabs.ultimate-guitar.com/d/deep_purple/smoke_on_the_water_tab.htm
Video Lesson - http://www.youtube.com/watch?v=gc6QQy17zz
FOLK & Traditional
Navigator
http://www.youtube.com/watch?v=2t3Qe3X-83A -> VIDEO
http://www.azchords.com/p/pogues-tabs-5469/navigator-tabs-155047.html -> CHORDS
Spancil Hill
http://www.youtube.com/watch?v=K2nlQ_mo3Gg -> VIDEO
http://tabs.ultimate-guitar.com/c/corrs/spancil_hill_crd.htm -> CHORDS
Greensleeves
http://www.youtube.com/watch?v=33Ja6ZcdS8w&feature=related -> VIDEO
http://tabs.ultimate-guitar.com/m/misc_traditional/greensleeves_crd.htm -> CHORDS
GAME SOUNDTRACK
Halo Theme
Tab - http://tabs.ultimate-guitar.com/h/halo/halo_theme_tab.htm
Video Lesson - http://www.youtube.com/watch?v=MKzbf2MeokQ
Age Of Empires 2 intro
Tab - http://tabs.ultimate-guitar.com/m/misc_computer_games/age_of_empires_2_age_of_kings_theme_intro_tab.htm
Couldn't find a video
Please post additions. :)
CLASSIC ROCK
Smoke on the Water(intro/main riff is easiest) - Deep Purple
Tab - http://tabs.ultimate-guitar.com/d/deep_purple/smoke_on_the_water_tab.htm
Video Lesson - http://www.youtube.com/watch?v=gc6QQy17zz
GAME SOUNDTRACK
Halo Theme
Tab - http://tabs.ultimate-guitar.com/h/halo/halo_theme_tab.htm
Video Lesson - http://www.youtube.com/watch?v=MKzbf2MeokQ
Age Of Empires 2 intro
Tab - http://tabs.ultimate-guitar.com/m/misc_computer_games/age_of_empires_2_age_of_kings_theme_intro_tab.htm
Couldn't find a video :(
Added, thanks! :)