Here's the original question:
Here's NEW the answer. I found ANOTHER one, so now its SIX actors.
- Hugo Weaving (Elrond) LOTR & The Matrix (Mr. Smith)
- Orlando Bloom (Legolas) LOTR & Pirates of the Carribean (Will Turner)
- Ian McKellan (Gandalf) LOTR & X-Men (Eric Lehnsherr / Magneto)
- John Rhys-Davies (Gimli and Treebeard) LOTR & Indiana Jones (Sallah)
** He didn't appear in "The Temple of Doom"
- Christopher Lee (Saruman) LOTR & Star Wars (Count Duki / Darth Tyranus)
*** Star Wars II & III (I consider them 2 separate trilogies) - check LOTR:Return of the King EXTENDED version (to consider him in all 3)
- Ian Holm (Bilbo) LOTR & the Alien Quadrilogy (Ash)
*** LOTR 1 & 3; Bilbo did not appear in "Two Towers" - He was only in "Alien", the first of the "Quadrilogy". Also interesting, is that Ian played in "Aliens" with John Hurt who had just played Aragorn in the first "Lord of the Rings" movie in 1978.