The Undertaker has been in the WWF/E for about twenty years arguabley each year being better than his last. But what do you think was the year of The Undertaker?
1990- Made his debut at the Survivor series, was managed by Brother Love & adapted the "Kane the Undertaker" gimmick.
1991- Dropped the "Kane the Undertaker" gimmick and was managed by Paul Bearer. Together they hosted the Funeral Palor. Taker also received his first Wrestlemania victory. And his First WWE Championship. Since his debut he was undefeated for a year. (I think)
1992- Originally being a heel he turned into a babyface, feuding with Jake "The Snake" Roberts and Kamala.
1993- Appeared on the very first episode of Raw feuded with Giant Gonzales.
1994- Undertaker was assulted at the Royal Rumble and wasn't seen on tv for weeks. He feuded with Yokazuna and the "Fake Undertaker" afterwards.
1995- Didn't do much (not that I know anyway) feuded with Kama and King Mabel.
1996- Feuded with Diesel, Mankind, and Paul Bearer after Bearer betrayed him. Competed in the first ever Buried Alive match and won.
1997- Won the WWE championship for the second time at Wrestlemania. Feuded with Bret Hart and Shawn Michaels competing in the first ever Hell In A Cell Match.
1998- Feuded with Kane, Mankind, Steve Austin. Teamed with Steve Austin and Kane. Won the World Tag Team Championship with Steve Austin. Turned heel again after his alliance with Kane. Competed in the first ever Inferno match, another Buried Alive match and two more Hell In A Cell matches.
1999- Formed the Ministry of Darkness and was apart of the Corporate Ministry. Reformed with Paul Bearer. Fought in another Inferno and buried alive match. Won his 3rd WWE title, and became World Tag Champs with Big Show twice. Feuded with Vince McMahon, The Rock, Stone Cold, Kane, Mankind.
2000- Turned into a babyface. Debuted a new gimmick after an injury. Feuded with DX/McMahon Helmsley Fraction, E&C, The Rock. Won the Tag Title with The Rock
2001- Feuded with 2-Man Power Trip, KroniK, DDP, The Alliance. Became tag champs with Kane 3 times. Turned heel.
2002- Became Undisuted champion, feuds with Hulk Hogan, HHH, The Hardy's, UnAmericans, Brock Lesnar. Another Hell In A Cell match.
2003- Feuds with A-Train, Big Show, John Cena, Brock Lesnar, Vince McMahon. Another Buried Alive match. First ever Biker Chain match.
2004- Returned with his old gimmick, Feuds with Kane, Booker T, JBL, Dudleyz, Heidenreich. First ever Concrete Crypt match.
2005- Feuds with Randy Orton, Muhammad Hassan, another Hell In A Cell match.
2006- Returned at the Royal Rumble, feuded with Kurt Angle, Great Khali, Mark Henry, Mr. Kennedy.
2007- Won his first ever Royal Rumble. Won his first World Heavyweight Championship. Feuds with Mark Henry, Batista, Edge. Hell In A Cell again.
2008- Feuds with Edge, Edgeheads, Big Show. Hell in a Cell. Won the World title again.
2009- Feuds with Shawn Michaels, Kozlov, CM Punk, Batista. Another Hell in a Cell and World title run.
2010- Feud with Shawn Michaels and now is currently in a vegetated state....tbc
I'd put a picture here but I don't know how

1990- Made his debut at the Survivor series, was managed by Brother Love & adapted the "Kane the Undertaker" gimmick.
1991- Dropped the "Kane the Undertaker" gimmick and was managed by Paul Bearer. Together they hosted the Funeral Palor. Taker also received his first Wrestlemania victory. And his First WWE Championship. Since his debut he was undefeated for a year. (I think)
1992- Originally being a heel he turned into a babyface, feuding with Jake "The Snake" Roberts and Kamala.
1993- Appeared on the very first episode of Raw feuded with Giant Gonzales.
1994- Undertaker was assulted at the Royal Rumble and wasn't seen on tv for weeks. He feuded with Yokazuna and the "Fake Undertaker" afterwards.
1995- Didn't do much (not that I know anyway) feuded with Kama and King Mabel.
1996- Feuded with Diesel, Mankind, and Paul Bearer after Bearer betrayed him. Competed in the first ever Buried Alive match and won.
1997- Won the WWE championship for the second time at Wrestlemania. Feuded with Bret Hart and Shawn Michaels competing in the first ever Hell In A Cell Match.
1998- Feuded with Kane, Mankind, Steve Austin. Teamed with Steve Austin and Kane. Won the World Tag Team Championship with Steve Austin. Turned heel again after his alliance with Kane. Competed in the first ever Inferno match, another Buried Alive match and two more Hell In A Cell matches.
1999- Formed the Ministry of Darkness and was apart of the Corporate Ministry. Reformed with Paul Bearer. Fought in another Inferno and buried alive match. Won his 3rd WWE title, and became World Tag Champs with Big Show twice. Feuded with Vince McMahon, The Rock, Stone Cold, Kane, Mankind.
2000- Turned into a babyface. Debuted a new gimmick after an injury. Feuded with DX/McMahon Helmsley Fraction, E&C, The Rock. Won the Tag Title with The Rock
2001- Feuded with 2-Man Power Trip, KroniK, DDP, The Alliance. Became tag champs with Kane 3 times. Turned heel.
2002- Became Undisuted champion, feuds with Hulk Hogan, HHH, The Hardy's, UnAmericans, Brock Lesnar. Another Hell In A Cell match.
2003- Feuds with A-Train, Big Show, John Cena, Brock Lesnar, Vince McMahon. Another Buried Alive match. First ever Biker Chain match.
2004- Returned with his old gimmick, Feuds with Kane, Booker T, JBL, Dudleyz, Heidenreich. First ever Concrete Crypt match.
2005- Feuds with Randy Orton, Muhammad Hassan, another Hell In A Cell match.
2006- Returned at the Royal Rumble, feuded with Kurt Angle, Great Khali, Mark Henry, Mr. Kennedy.
2007- Won his first ever Royal Rumble. Won his first World Heavyweight Championship. Feuds with Mark Henry, Batista, Edge. Hell In A Cell again.
2008- Feuds with Edge, Edgeheads, Big Show. Hell in a Cell. Won the World title again.
2009- Feuds with Shawn Michaels, Kozlov, CM Punk, Batista. Another Hell in a Cell and World title run.
2010- Feud with Shawn Michaels and now is currently in a vegetated state....tbc