When you look at the list of legendary chess world champions, and you see the name Ponomariov among them, don't you feel he doesn't belong there?

Yea, I have forgot about Khalifman too, it's truly a joke and a damage to world championship repetition.

I don't know about all that. He is one of the top 10 players in the world currently sooooooooooo... guess he is strong enough

Ruslan is a legitimate contender now but, like Khalifman, he was nowhere near a world-class player when he won his FIDE "title."

I don't consider any of the tournaments legitimate for WC, except for 1948 when Alekhine had died.  But the title should be passed by individual matches, and along the line of succession which reaches back to Steinitz (with the one leap after the death of Alekhine, and Fischer's default).  So to me the WC who were legitimate holders of the title have been (after Fischer) Karpov, Kasparov, Kramnik, and Anand.

I don't count Anand's or Topalov's tournament titles, either.

I think history will agree with this assessment.

I count Anand's 2007 since it was agreed by Kramnik and all other participants that this format was valid. I'd count a tournament as valid also today if Anand and the other players agreed with it. The knockout titles were dubious because neither the other World Champion nor the highest rated player participated. In 2007 there were no alternative World Champion, only Anand, and no player questioned that the tournament was for the World Championship. If Anand is questioned one could just as well question Kramnik since what he won in 2000 was Kasparov's private title and that after losing the Candidates.

And there's also Kasimdzhanov. Great guy, I love his DVDs, and he's briefly been 2700+, but world champion?

I wonder how history would have remembered Botvinnik if it wasn't for the rematch clause. A flash in the pan that after some (alegedly) cheating won the WC in a 1948 tournament, only to lose it quickly after.

I think Botvinnik would be remembered very differently if it wasn't for the rematch clause.