Edit: Okay, this should be everyone since the 1967 expansion
Durations I could find of 25+ years
Gordie Howe entered the top 10 on March 18th, 1954. He is still there.
Phil Esposito entered the top 10 on January 5, 1974. He left on April 11, 2024 (Crosby)
Marcel Dionne entered the top 10 on November 25, 1981. He is still there.
Wayne Gretzky entered the top 10 on January 8, 1986. He is still there.
Stan Mikita entered the top 10 on February 4, 1970. He left on April 17, 1999 (Bourque)
Mark Messier entered the top 10 on January 31, 1994. He is still there.
Mario Lemieux entered the top 10 on April 14, 1996. He is still there.
Ron Francis entered the top 10 on February 25, 1998. He is still there.
Steve Yzerman entered the top 10 on November 11, 1998. He is still there.
Alex Delvecchio entered the top 10 on November 18, 1962. He left on January 31, 1994 (Messier)
Johnny Bucyk entered the top 10 on February 11, 1971. He left on April 14, 1996 (Lemieux)
Howie Morenz entered the top 10 on February 7, 1928. He left on February 5, 1952 (Clapper)
Some others
Bryan Trottier entered the top 10 on January 8, 1988. He left on November 11, 1998 (Yzerman)
Paul Coffey entered the top 10 on April 19, 1995. He left on January 1, 2007 (Sakic)
Ray Bourque entered the top 10 on April 17, 1999. He left on February 19, 2008 (Jagr)
Jean Ratelle entered the top 10 on January 26, 1978. He left on December 4, 1988 (Lafleur)
Guy Lafleur entered the top 10 on April 3, 1983. He left on January 8, 1988. He rejoined on December 4, 1988. He left on February 29, 1996 (Hawerchuk)
Gilbert Perreault entered the top 10 on February 3, 1985. He left on April 19, 1995 (Coffey).
Dale Hawerchuk entered the top 10 on February 29, 1996. He left on February 25, 1998 (Francis)
Norm Ullman entered the top 10 on October 27, 1966. He left on January 11, 1967 (Hull). He rejoined on November 25, 1967. He left on January 8, 1986 (Gretzky).
Jean Beliveau entered the top 10 on December 4, 1960. He left on February 3, 1985 (Perreault).
Bobby Hull entered the top 10 on March 12, 1966. He left on October 27, 1966 (Ullman). He rejoined on January 11, 1967. He left on April 3, 1983 (Lafleur).
Frank Mahovlich entered the top 10 on October 21, 1972. He left on November 25, 1981 (Dionne).
Henri Richard entered the top 10 on November 20, 1965. He left on November 25, 1967 (Ullman). He rejoined on January 31, 1970. He left on October 21, 1972 (Mahovlich). He rejoined on February 16, 1973. He left on January 26, 1978 (Ratelle)
Maurice Richard entered the top 10 on February 22, 1951. He left on February 16, 1973 (H. Richard)
Ted Lindsay entered the top 10 on January 13, 1954. He left on February 11, 1971 (Bucyk)
Bernie Geoffrion entered the top 10 on October 29, 1960. He left on January 31, 1970 (H. Richard)
Red Kelly entered the top 10 on February 23, 1961. He left on February 4, 1970 (Mikita)
Andy Bathgate entered the top 10 on January 13, 1962. He left on January 5, 1974 (Esposito)
So it works out to
1. Gordie Howe - 25,594 days (70 years)
2. Phil Esposito - 18,359 days (50 years)
3. Marcel Dionne - 15,480 days (42 years)
4. Wayne Gretzky - 13,975 days (38 years)
5. Alex Delvecchio - 11,397 days (31 years)
6. Mark Messier - 11,030 days (30 years)
7. Stan Mikita - 10,694 days (29 years)
8. Mario Lemieux - 10,226 days (27 years)
9. Ron Francis - 9,544 days (26 years)
10. Steve Yzerman - 9,285 days (25 years)
11. Johnny Bucyk - 9,194 days (25 years)
12. John Beliveau - 8,827 (24 years)
13. Howie Morenz - 8,764 days (23 years)
14. M. Richard - 8,030 (21 years)
15. Norm Ullman - 6,696 days (18 years)
16. Joe Sakic - 6,312 days (17 years)
17. Bobby Hull - 6,155 days (16 years)
18. Jaromir Jagr - 5,898 days (16 years)
19. Ted Lindsay - 5,862 days (16 years)
20. Guy Lafleur - 4,386 days between the two times (12 years)
21. Andy Bathgate - 4,375 days (11 years)
22. Paul Coffey - 4,275 days (11 years)
23. Jean Ratelle - 3,966 days (10 years)
24. Bryan Trottier - 3,960 days (10 years)
25. Gilbert Perreault - 3,728 days (10 years)
26. Henri Richard - 3,534 days (9 years)
27. Bernie Geoffrion - 3,381 days (9 years)
28. Frank Mahovlich - 3,322 (9 years)
29. Red Kelly - 3,268 days (8 years)
30. Ray Bourque - 3,230 days (8 years)
31. Dale Hawerchuk - 728 days (1 year)
32. Sidney Crosby - 2 days
Sakic has a chance of getting ousted by Ovechkin. It would happen some time early in the 25-26 season when Ovechkin is 40. Jagr will hold on a top 10 spot forever.
For active players, outside Ovechkin and McDavid it'll be hard to see anyone breaking in. Sakic's 1641 points or Lemieux’s 1723 points will be the 10th spot for years. Kucherov is almost 31 and is just halfway there.
It gets harder and harder to break in.
That Howe has held a spot for 70 years is mind blowing.