Doom's beaten the Magus and Warlock, and those fights were actual fisticuffs. With regards to his magical abilities, during the Triumph & Torment storyline: after the contest where Doom and Strange beat all the other sorcerers, Strange actually trains Doom before they venture off to hell. Better than Dr Druid, Baron Mordo? Better believe it, after being trained by Strange. Plus I didn't see those two in the tournament, and the invitation was only sensed by those most attuned to mystical forces.
It is a bit silly that people attempt to make Doom look lame by going "Hahaha you lost to the Fantastic Four."
Hello? He lost to the Fantastic Four.
We're not talking about Alpha Flight, we're talking about the Fantastic Four.
The fact that they fight Galactus and shit, yet Doom is their main villain, says enough.
-AC
"Magneto has always been portrayed as Doom's b!tch...he totally punked him in FF vs X-Men"
Magneto: I shall now use my powers to manipulate your armo....
*Doom takes helmet*
Doom: Yoink!
*Wears Mags' helmet*
Doom: Look at me! I'm Magneto! I'm controlling stuff! Would you like some hair dye? I would because I'm Magneto.
-AC
He didn't punk him in X-men vs. FF. Magneto smacked Doom around, Doom then de-magnitized his armor, and punched Magneto, then the fight ended. It was hardly conclusive. IRTMU called it when he said all the different ways Magneto can end this. Magneto has overcome magnetic shielding before. No reason he couldn't do it to Doom in an extended battle.