Best chess player who ever lived?

<<"We are tall today because we stand on the shoulders of giants". And the biggest "giant" of them all? Bobby Fischer!>> well put and I agree 100%!

I'm a FIDE Master from Romania (current ELO rating 2344) and I've played (and drawn most of the time, never won and lost 1-2 games) against a few 2600s in my career (most recently Mircea Parligras, who made it to Round 3 at the latest World Cup, who I drew with Black, earlier this year, after a hard-fought game), plus I've seen a number of 2700 players in action (and analyzed for a bit with at least one that was close to that figure at the time), so I can lay claim to having some knowledge of what a strong player means these days. Personally I'd add to that the fact that I've read (and analyzed many games from) Kasparov's books on his predecessors more than once (his books giving wonderful
insights into the world of top class chess from every decade) but I guess they're too recently published for people to have such a high opinion of them as I do yet.
Anyway, the idea is that, knowing all that I do, I personally still consider Fischer to be the most dominant (this point can be proven mathematically) and even best overall player of all time, due to the incredible accuracy of his calculation, his impeccable understanding of the game, his amazing endgame technique, the very, very low frequency of mistakes in his games, his unbreakable will and, of course, his outstanding opening preparation (which, if he had been born more recently, would easily have been adjusted to modern requirements, thanks to his tremendous capacity for effort, making him an even better prepared player than Kasparov, IMO). He is the player whose style I admire the most.
However, as Vespassian anticipated, I would have to say that, having talked to many fellow chessplayers (including Grandmasters) the generally prevailing opinion among them is that Kasparov is the best ever. I attribute that to their underestimating the magnitude of rating inflation, their overestimation of the development of chess theory and its importance toward the general level of play - having watched hundreds, perhaps thousands of recent top GM games I can honestly say they ALL make AT LEAST as many mistakes under pressure as Fischer did in his time, even though their opening and endgame play might be slightly more accurate - and their failure to place enough importance on the context issue (meaning that they should think of Fischer's strength as a function of his calculating ability, positional understanding and his theoretical preparation IN RELATION TO the material and knowledge available at the time). Had Fischer been born, say, in the 1970s, he would have had the full benefit of today's knowledge and means of preparation which, coupled with his legendary capacity for effort and his natural talent, would, as the previous poster observed, have made him a player almost impossible to beat - that's just my opinion but I think it's pretty hard to argue against it. Obviously, most of the people I've spoken to about this are probably way more intelligent than I am, but I just think they haven't really given the issue as much thought as I have. I'll be open to changing my opinion in the future if somebody who has will refute my arguments (or at least most of them) or bring forth others in favor of some other player, be it Kasparov or not, which would trump my own.
Now, to address some of the aspects brought up in this thread:
- Morphy seems to have been slightly more talented than Fischer, so I agree that had he been born in today's world he could have (depending on the amount of work he would have been willing to put in - today talent is clearly not enough anymore) become even greater than Bobby;
- if we take absolute (and by this I mean inflation adjusted) ELO ratings from the late 1960's to the present time, Bobby Fischer's peak is the highest at 2785 - July 1972 - (there was no noticeable inflation up until 1986), Kasparov's is 2764 - January 1990 (so not even close); then comes Karpov (2725 in 1978 and 1980). Had ratings been calculated in their times, Capablanca, Lasker or Botvinnik may have surpassed Fischer's absolute peak, since Arpad Elo calculated their best 5-year average as being 2725/2720/2720, which would indicate their peak was definitely higher (unless they would have held steady at exactly 2725/2720 for 5 consecutive years, which is very unlikely). Yet it's not clear if they did ever pass 2785, as that is, after all, 60 points higher. In recent years inflation has been about 140-50 points, which means it's out of the question that any contemporary players will get to (a real) 2785 any time soon.
It should be noted that even Chessmetrics (as I write) gives Fischer as the highest rated player ever according to 1-year peaks (Kasparov overtakes him if the period is extended, but that was to be expected given the quite short duration of Fischer's stint at the very top of the chess world):
#1 Bobby Fischer 2881 1972-Jan through 1972-Dec
#2 Garry Kasparov 2879 1990-Jan through 1990-Dec
#3 Mikhail Botvinnik 2871 1946-Jan through 1946-Dec
#4 José Capablanca 2866 1919-Jan through 1919-Dec
#5 Emanuel Lasker 2863 1894-Jan through 1894-Dec;
- perfect scores have been achieved by other great players but NEVER against such strong competition as Fischer (his opponents in the US Championship he won 11-0 had an average rating of around 2450-2500, I would estimate, with players like Evans, Reshevsky, Benko, the Byrnes, Saidy, Bisguier, Addison and Mednis all playing, while Larsen and Taimanov were both around or over 2600, and we're not talking today's highly inflated ratings, so that's like 2750 in our times);
- "Winning 19 straight games at a grandmaster level will never be repeated, ever" except if inflation keeps going up, in which case Grandmaster level could very well mean something like a 2200-2300 average in absolute ratings soon, and therefore it wouldn't be so hard to make perfect scores at that level anymore. So we're really talking about top Grandmaster level, I guess;
- Yes, Kasparov did take the game to a new level, but so did Fischer in his day (Kasparov himself recognizes this and even dedicates an entire volume to the revolution started mainly by Fischer) and I see no reason to assume he wouldn't have also done that (in some other way) in the late '80s, had that been his time.

Sorry this is such a long message, but I feel very strongly about the issue of Fischer being the best player ever or not. I've not yet seen the documentary but I've been anxiously awaiting its release and will surely watch it as soon as I can.