Simeone led Atletico to a first La Liga title for 18 years in 2014, after winning the Europa League and King’s Cup in preceding seasons, and they are now in second place, level on points with Barca and a point above Real with three games left.
They also knocked Guardiola's former club Barcelona, the Champions League favourites and holders, out of this season's competition in the quarter-finals.
“The best title Atletico have achieved is that they are compared with Barcelona and Madrid, that’s Simeone’s greatest achievement,” Guardiola told a news conference on Tuesday.
“What they show is their consistency, that’s the most difficult thing, to win, win win. Normally only big teams do that, play three different competitions, game after game and win, win, win.
"The most difficult thing in sport is to win year on year. Anyone can win one year but to keep themselves at the top, that’s impressive."
Guardiola's Bayern also lost in the 2014 semis to eventual winners Real Madrid and the clash with Atletico is his last chance of reaching the Champions League final with the club before he takes charge at Manchester City for next season.
But the Spaniard said he was proud of his record in Germany, where he is on course to win a third straight Bundesliga title.
“I see it as good. In three years we’ve got to three semis. I know that people say if I don’t win the Champions League my work won’t be complete, but I’ve been very lucky to have experienced what I have in Germany," added Guardiola.
"I think I’m a better coach, a better guy, more relaxed.”
While Bayern have their eyes on a sixth European Cup, the first of which came against Atletico in 1974, the Spaniards are looking for their maiden triumph in Europe’s elite competition, also losing in the 2014 final, to Real Madrid.
“Atleti know what we’re playing for tomorrow, not just to get to the final, we’re playing for a chance to enter the club’s history and the fans will respond to this,” said captain Gabi.
Fernando Torres added: “The club’s has its colours and values. What we try to do on the pitch is transmit them. We’re convinced that if you believe, you can and we are going to try and do it.”
(Reporting by Richard Martin; Editing by Ken Ferris)
