The Dazzler: Kylie Minogue. Duh.
Dazzler's Dad & Mom: Tom Selleck & Caroline Rhea, because they not only look the part, they're as whiny as Dazzler is.
Doctor Doom: Let's see, Doctor Doom is a vain, preening old queen, who, like most leather queens, uses gear as an exo-skeleton for his sagging self-worth and masculinity. I guess the guy who played him in the FF movie will do just fine.
Enchantress: Shannon Dougherty is pretty much the only choice, isn't she?
Galactus: Ben Stein. If you need someone to look down on people as insects, who better? Besides, he's got the perfect voice for it. In your best Ben Stein voice, read the following and tell me I'm wrong:
"Yet, Galactus is above mere morality. Galactus is amoral. Galactus does what he must do in order to survive."
Replace the name 'Galactus' with the name 'Ben Stein', and it reads even better. Ben Stein was born to play Galactus.
The Grapplers (Titania, Poundcakes, Letha, & Screaming Mimi): The View.
Johnny Guitar & Doctor Sax: Hm. A guy who can ruin things with his guitar and one whose sax playing makes you want to commit suicide. Kurt Cobain and Kenny G would have been the logical choices, but I can't see that happening. Let's try Steve Zahn (because he does with his performance what Johnny does with a guitar) and Morgan Freeman (because every time he opens his mouth, it makes me want to commit suicide, and besides, federal law requires him to be in all major motion pictures at this point).
P.S. YES, I know they made a Dazzler movie within the comics. If you think that will stop from Marvel Entertainment from doing it in the real world, I have just two words for you: Ghost Rider.