Iron-Man/Tony Stark
When I was younger I used to watch A-Team and always thought that Dirk Benedict (Faceman) would be an excellent Tony Stark/Iron-Man. He looks just like Tony Stark in the pic that is on his IMDB profile, from the moustache and hair style to his facial features. I was a huge (still am) comic book fan and Dirk Benedict used to look so much like Tony Stark that I thought it was amazing, I dunno if anyone would agree.
As for Mandarin, I always thought James Hong would have been an excellent Mandarin after seeing his Lo Pan character in Big Trouble in Little China I was just convinced that they should make an Iron-man movie (this was during the late 80s to early 90s) with James Hong as Mandarin and Dirk Benedict as Tony Stark/Iron-man.
And guess who I always thought would be a good War Machine... LOL!!!
BILLY BLANKS!! Yes I know, but I was a kid and I used to love these mindless action films with kung fu kicking and martial arts!
But now I think my choices for Iron-man/Tony Stark are...!
Adrian Paul
Martin Henderson
Matthew McConoughey
David Boreanaz
Thomas Gibson
As for Jim "Rhodey" Rhodes/War Machine my choices are...
Michael Jai White
Laurence Fishnourne
Vingt Rhames
Kevin Grevioux
Lynn "Red" Williams
For Mandarin there are quite a few choices...
Ken Watanabe
Cary Hiroyuki Tagawa
Roger Yuan
Sonny Chiba
and for Justin Hammer...
Ronny Cox
Christopher Lee
Donald Sutherland
Sir Ian McKellen
So far these are my choices for the modern day Iron-man movie. do add more to it!