Probably only a few of the cast are remembered now. Maybe Stanley Baker and Sir Cedric Hardwicke being the two best known. Or Torin Thatcher. I, however, liked Rosanna Podesta a lot, and I didn't care that her dialogue was dubbed.
The plot pretty much sticks to Homer, and while I haven't seen this one in a while, I'd bet that it's more fun than 2004's Troy, which skimped on the spectacle.
Certainly Helen of Troy isn't a great movie, but it's entertainment in the grand style.