I have been playing guitar for almost five years now and I have gotten almost as good (and fast) as I can get (of course not perfect but I can play anything if I spent time with it) but I never really bothered to learn scales since I can find the right notes to play for a solo (I basically find the scale that I am in and doodle around in it until I make up something good and memorize it).
So it is necessary (or viatally important) for me to learn and memorize scales on guitar?
I plann on learning some scales this year when I get time anyways but what are the most important scales that I should learn?
Please reply, it would be greatly appreciated.
Minor Pentatonic,
Harmonic Minor,

Those are the coolest in my opinion, majors not cool but it fits really good riffs in some places. Youll probalby find youve made up scales that are actually scales.
The major scale is the cornerstone of very nearly all Western theory. Learn it in every key, all over the fretboard, as well as the theory behind it.
Someones knowledge of guitar companies spelling determines what amps you can own. Really smart people can own things like Framus because they sound like they might be spelled with a "y" but they aren't.
I think I understand minor scales now, I looked up some lessons earlier on the Major G (minor G, melodic G, petonic(A) G, and petonic(B) G) Scale and the basic concept of minor (WHWWHWW right?)
i just have to memorize all the major scales first and then I should have the minors done automatically as long as I memorize that patter?
IMO, the order to learn it is first major/minor pentatonics, then the natural major and minor, then the other major and minor modes. Think of the natural major and minor as filling in the gaps in the pentatonics, then think of the other modes as variations on these. For instance, think of the Dorian as the Aeolian with a sharpened 6th. You shouldn't think of the modes as "the major scale starting on a different note", not to begin with anyway. I mean, it's true, but it's a historical curiosity and a convenient calculation tool, not their fundamental definition. They're just scales at the end of the day.

It's when you start relating the patterns to chords that that little "curiosity" starts becoming useful. Lets say you're in the E Aeolian, and you're hovering over a D major chord. Try the chord played like this...


...with your thumb fretting the bass string. Then try a few licks over the top. Your pattern, with your hand fixed around your thumb, then becomes the D Mixolydian of course. So as I say, it's very convenient and definitely has its uses.

Other than the modes, there's the harmonic minor which is reasonably common. Usually, this is used only over a substituted chord V (made major) in an otherwise modal progression (for instance Sultans of Swing or Babe I'm Gonna Leave You).

I don't consider the blues scale to be different from the minor pentatonic, in that you can use either whenever you could use the other. Learn those two side by side.
well thats should definetly keep me busy for a while, but one last question.
what are some important scales that i could memorize for metal?
and what about scales for depressive stuff? (those are the basic styles that I play)