The limit of age to be considered this generation or young is 35, Leonardo DiCaprio is already established with heaps of interesting roles ahead in his career. (The same with Matt Damon, Christian Bale, etc.)
1. Jake Gyllenhaal (Brothers)Jake Gyllenhaal is an even tempered, sporty guy. His method performance as Donnie Darko was enough to curdle our blood and it foreshadowed a brilliance we would fortunately rediscover in Brokeback Mountain and Zodiac.
2. Joseph Gordon-Levitt (Inception)Drawn instinctively to a creativity streak, Joseph Gordon-Levitt captures our attention without imposing on our way, he jumps very high scenic turnpikes and shows the scars down the road.
3. Emile Hirsch (Hamlet)Emile Hirsch has a nice matey quality, which he exposed to open view in "The Girl Next Door", he trespassed the 4th wall in "Into the wild", and has rewritten/updated "Hamlet", his last film project.
4. Ryan Gosling (Blue Valentine)Confidence is one of the main Ryan Gosling's acting weapons. He has this anonymized charm, an inviting seriousness in all his roles that always let us starving for more.
5. James McAvoy (The Last Station)Atonement was a statement of attainment. His exactness, structured approaching to his craft, and his unmeasurable British charisma win over bedazzled public and critics.
6. Daniel Brühl (Inglorious Basterds)Brühl becomes the incarnation of Nazi laureate soldier's contradictions, as the stubborn Pvt Fredrick Zoller infatuated with Shosanna, a theatre owner Jew survivor woman.
7. Paul Dano (Gigantic)Maybe Dano's ability to convokate positive acknowledgement doesn't reside primarily in sex-appeal, but in his virtue of underplaying complex emotional reactions.
8. Gael García Bernal (Letters to Juliet)García Bernal played a victim of Catholic priest's abuse, and he was in return anointed by press priests. Cruel in "Blindness", soft in "The Science of sleep", he's capable of convening viscerality and sensuality onscreen.
9. Michael Angarano (Ceremony)Angarano's persuasive powers are his childish smile that feels like a gift even in their more disillusioned characters as in Snow Angels, and aplenty sincerity that oversteps the camera's limits.
10. James Franco (Howl)James Franco was eye-catching as Harvey Milk's true love, Scott Smith. His kiss with Sean Penn at New York's subway station and his relationship seen through Castro Camera's windows is a hit for gay rights and love stories.
11. Shia Labeouf (Wall Street 2: Money never sleeps)Seeing beyond his HW conceited person, Labeouf's career is a rounded success after another, he is easily likeable as the hormonal ridden, good hearted average boy, maybe this is the secret of his wide acceptation.
12. Michael Cera (Scott Pilgrim vs. the world)Cera is the king of dramatic irony, monotonous niceness, a symbol of teenage self-consciousness, yet a mature act ahead of his years.
13. Seth Rogen (Funny People)Rogen's lovable comedic antics, abandoned bluntness combined with bold slacker attitude turn him into a sort of "anti-dreamboat".
14. Anton Yelchin (The Beaver)Yelchin looks a toddler but he's already an experienced young actor who will grown up facing his new challenge as Porter in The Beaver -directed by Jodie foster- an adolescent terrified of becoming his father.
15. Jamie Bell (The Adventures of Tintin: The secret of the Unicorn)Bell was initially the big promise of British cinema, now a sovereign international actor, free-time writer, who can take up his roles seriously or lightness, always with a distinctive twist.
16. Robert Pattinson (The Twilight saga: Eclipse)He's the up to the minute heartthrob thanks to Twilight franchise and tabloid fodder overreliance that often accompanies his competent acting work.
1. Jake Gyllenhaal (Brothers)
2. Joseph Gordon-Levitt (Inception)
3. Emile Hirsch (Hamlet)
4. Ryan Gosling (Blue Valentine)
5. James McAvoy (The Last Station)
6. Daniel Brühl (Inglorious Basterds)
7. Paul Dano (Gigantic)
8. Gael García Bernal (Letters to Juliet)
9. Michael Angarano (Ceremony)
10. James Franco (Howl)
11. Shia Labeouf (Wall Street 2: Money never sleeps)
12. Michael Cera (Scott Pilgrim vs. the world)
13. Seth Rogen (Funny People)
14. Anton Yelchin (The Beaver)
15. Jamie Bell (The Adventures of Tintin: The secret of the Unicorn)
16. Robert Pattinson (The Twilight saga: Eclipse)
17. Jesse Eisenberg (Zombieland)
18. Patrick Fugit (Cirque du Freak: The Vampire's Assistant)
19. Ben Whishaw (Brightstar)
20. Ben Foster (Pandorum)
21. Dominic Cooper (Tamara Drewe)
22. Channing Tatum (Dear John)
23. Henry Cavill (Whatever works)
24. Ryan Donowho (Cook County)
25. Eddie Redmayne (The Yellow Handkerchief)
26. Lou Taylor Pucci (Carriers)
27. Gaspard Ulliel (The Vintner's Luck)
28. Joe Anderson (Becoming Jane)
29. Chris Marquette (Infestation)
30. Andrew Garfield (The Imaginarium of Doctor Parnassus)
31. Adam Brody (Jennifer's Body)
32. Chris Pine (Unstoppable) 
33. Aaron Johnson (The Greatest)
34. Ben Barnes (Dorian Gray).jpg)
35. Michael Welch (Unrequited)
36. Jensen Ackles (My Bloody Valentine)
37. Nicholas Hoult (About a boy)
38. Lucas Grabeel (Smoke Break)
39. Jim Sturgess (Upside Down)
40. Rupert Grint (Wild Target) 
41. Xavier Samuel (The Loved ones)
42. Matt O'Leary (Jake's Run) 
43. Mark Duplass (True Adolescents)
44. Marshall Allman (The Immaculate Conception of Little Dizzle)
45. Luke Treadaway (Heartless)
46. Ryan Kwanten (Griff the Invisible)
47. Jay Baruchel (Nick & Norah's Infinite Playlist)
48. Eduardo Noriega (Che Guevara)
49. Juan José Ballesta (Bruc)
50. Jason Fuchs (The last first time)