What are the fundamental pros and cons to defensive chess play?

With regards more defensive chess players, what are the overall advantages and disadvantages to playing defensively, as opposed to offensively? Are there any tactical, positional, time or psychological advantages?

+ Do you know any famous chess players who favoured a more defensive play?

Thanks

Tigran Petrosian pointed out that defensive play is extremely risky, and he's perhaps the greatest defensive player ever.

Chess is a game that rewards the initiative. Defense is essential to being a good player, but if you want to excel at defense, you must be able to sniff out attacks before your opponent is aware of those attacking possibilities. It takes even better tactical awareness to play well defensively than it does to play aggressively!

And let's not confuse defensive play with passive play. A passive position is gonna get killed by a strong player.

If you're interested in great defensive players, take a look at Emanuel Lasker, Tigran Petrosian, Viktor Korchnoi (a quintessential counter-attacker), Ulf Anderssen, Anatoly Karpov, and Vladimir Kramnik. Those are probably the half-dozen greatest defensive players ever.

I'm currently looking through Petrosian's games, not because I myself am defensive, but because club players are typically lacking in this area, and club players love to attack and look for tactics. 

That's interesting stuff - I always used to think offensive play was more risky because in my experience offensive play is usally quicker and, if lacking in proper defence, leaves key pieces exposed. Will look at Petrosian now

Can't argue with SmyslovFans choices, but I'd like to add Capablanca to his list as well. Aside from having a phenomenally low losing percentage (5%) I don't think he hardly ever lost when he was a pawn up no matter how violent a gambit or attack he faced. And of course many world-class GMs are almost equally good at attacking and defending - but we probably don't think of Fischer for instance as being a great defender because he probably didn't have to most of the time - but when he did I'm sure he was right up there with Petrosian et al but just not as often due to his different style of play.

As far as overall advantages/disadvantages of defensive play, a good rule of thumb is if you've got a sound attack (or initiative) and you blow it, you might lose a pawn or get an even or inferior position. When you're defending and you blow it there's a good chance you're going to lose lots of material or end up in a grossly inferior position - unless you get mated first that is. It's also a real drag to have to play "reactive" chess in answer to your opponent's threats instead of "proactive" chess where you've got the initiative and your opponent has to try neutralizing whatever threats or plans you come up with - like queening a passed pawn, winning material, bearing down on a backward pawn or whatever.