When I say that Castlevania was great, I mean strictly small period of time 87-91.
We go from sales to discussing when Castlevania was "great"? : T
Well, if we're going to do that, I think it was great from 2002 to 2003 : D
Anyway, Castlevania has always been a very well respected video game series, but it's never had an earth-shattering release like Super Mario Bros. and SMB3, Street Fighter II, Metal Gear Solid, Final Fantasy VII, The Legend of Zelda: Ocarina of Time, Halo, or Pokemon Red and Blue. Those are, what I believe, most people would consider giants in the video game industry. It would be difficult to prove otherwise. To think Castlevania has had a release as financially successful or influential as any of those would be deluding yourself.
I don't know what all this talk is of Mega Man, because, from my perspective, I don't think it's much better off, if at all. It was a big deal on the NES (for a time) and had some success on the SNES, but... what was Mega Man X compared to Mortal Kombat and Street Fighter II? I think the recent downloadable games made a big splash because they were novel ideas, which no one had ever seen anything like at the time. Well... they had seen something just like them years and years ago... but you know... It was a good idea and the right time for it.
I think Castlevania is cool (well, it has been on really shaky ground to me ever since 04 or so, with a few hits but so many misses), but let's not let our fandom uproot us from reality.