The game has a lot of flaws. The Inverted Castle is crap(and that is a very bad thing considering it's the second half of the game), most of the weapons are useless, there are a lot of unnecessary things just thrown in for kicks, it has a lot of glitches, the game feels incomplete and probably is, and the game is mind bogglingly easy. If it ever gets remade(again, and when it's a good time for it), it should get fixed because it's in dire need of that in many ways. SotN definitely does not deserve its title as "best Castlevania game ever".
I guess I can understand not liking the inverted castle, but I find it fun, the bosses are all completely new, and it's far less repetitive and stupid than AOS' "second castle," which as I recall is exactly the same thing. (That was AOS and not HOD, right? Maybe I'm confused.)
AOS, DOS, and POR have useless weapons also, but despite that the variety is fun regardless--or at least I find it fun in SOTN. The other games, not so much. SOTN has soooo many weapons and items that you really don't ever need to use, but it's fun at least once to go through them all and see the neat little things some of them do. Same with all the items--especially the ones that cause huge naked chicks to appear on the screen. Throwing peanuts in the air and trying to catch them in your mouth to regain just a few points of health? Come on! Little details like that are so much fun! The other games have very few such tiny, useless, albeit fun details.
What are these "unnecessary things" you speak of? 'Cos I love all the weird little details and things in the game. Makes it feel far more complete than the other games.
Glitches? Yeah, there are the well-known glitches, some of which cause the progress percentage of the game to go higher--so are they really glitches, or intentional? Either way, they're fun, and I've NEVER done anything in the game that has somehow screwed me over. Seriously, when has a glitch in SOTN ever ruined your play experience? None of it gets in the way. Besides that, some of the other games have glitches also. Being able to go outside of the castle in AOS (or was that DOS)? You're not just going to look over that, are you?
What makes SOTN feel incomplete? I hope you don't say "'cos it doesn't have the ability to play Maria and the new areas like in the Saturn version," because those were all added LATER and as far as I know were not intended to be put in the original game. I've never played the Saturn version, but I hear the new areas are poorly-designed, the new sprites suck ass, and there's nothing special about the new tunes either (which, if I'm not mistaken, weren't even written by Yamane).
Yeah, the game is easy, but aside from COTM, are any of the other Metroidvanias anything more than a cakewalk? Seriously. ALL of IGA's SOTN-style Castlevanias are a breeze. Except that none of those other games have the insane challenge of a boss like Galamoth. Sure, the boss is pretty easy to get through if you have the right equipment and/or the fairy familiar healing you constantly, but he's still a pretty darn tough cookie. COTM is the only Metroidvania that really poses a consistent challenge.
As for SOTN being considered the best Castlevania, yeah I agree it doesn't quite deserve that title, but it certainly is deserving of its high praise and being considered ONE of the best. And it's so good that I honestly don't mind if somebody DOES think it's THE best, because it really IS so good. And if nothing else, arguing that any of the other Metroidvanias are superior or come even close to its brilliance and replayability is just a dead argument from the start because it's simply not true. :)