From the NA Nintendo YouTube channel (and Mega64 channel for the E3 video):
General Directs in 2012
Nintendo Direct 2.22.12 - 376,021
Nintendo Direct 6.21.12 - 471,805
Nintendo Direct 10.25.12 - 94,648
Nintendo Direct 12.5.12 - 102,860
Special Directs in 2012
Nintendo Direct Pre E3 2012 - 1,018,447
Wii U Preview Presentation (a little cheating, but, elsewhere, it was a Direct, so...) - 282,589
Nintendo Direct Mini - NSMB2 - 473,686
Nintendo Direct Mini: NSMB2 - 11.27.12 - 70,519
General Directs in 2013
Nintendo Direct: Wii U Games - 389,898
Nintendo Direct 2.14.2013 - 342,403
Nintendo Direct 4.17.2013 - 320,551
Nintendo Direct 5.17.13 - 222,432
Nintendo Direct 8.7.13 - 231,640
Nintendo Direct 10.1.13 - 222,975
Nintendo Direct 11.13.13 - 240,701
Nintendo Direct 12.18.13 - 342,515
Special Directs in 2013
Pokémon Direct 1.8.2013 - 628,874
Nintendo Direct @E3 2013 - 1,702,197
Nintendo Direct Mini 7.18.13 - 192,309
The Wonderful 101 Direct 8.9.13 - 76,652
Pokémon Direct 9.4.13 - 314,547
Wii Fit U Direct 9.18.13 - 93,926
Nintendo Direct: 3DS Louvre Guide - 54,740
General Direct in 2014, as of June 5th, 2014, 10:35 GMT
Nintendo Direct 2.13.14 - 487,070 - 7,222 likes / 286 dislikes
Special Directs in 2014
Super Smash Bros. Direct - 4.8.14 - 1,431,938 - 29,010 likes / 280 dislikes
Tomodachi Life Direct 4.10.14 - 701,835 - 13,487 likes / 312 dislikes
Mario Kart 8 Direct 4.30.14 - 696,083 - 14,124 likes / 224 dislikes
Play Nintendo 4.29.14 - 848,169 - 22,992 likes / 471 dislikes
Mega 64 infiltrates Nintendo - 91,307 - 5,031 likes / 93 dislikes
Total - 939,476 - 28,023 likes / 564 dislikes
Play Nintendo - Super Smash Bros. Invitational @ E3 2014 5.29.14 - 941,341 - 11,340 likes / 417 dislikes