Everyone is different with Jazz. I got into it by comparing the old blues of the 1920's to the 1970's classic rock. Nat King Cole, Louis Armstrong, Bix Biderbeck, Duke Ellington and Count Basie are all guys in this era; Dixieland up to Big band. Then the late 1930's hit and Glenn Miller and Big band style came out. A lot of dancing music here. So if you like to dance, I'd start there. Now for someone that enjoys metal, I'd assume you like complex music, something to keep you on your toes, go for bebop of the 1940's. Charlie parker, Dizzy Gillespie, Charlie Christian, those three were the main leaders of the bebop movement and I'd suggest to start there. Now, as a preface to jazz, it's VERY rich in history and not like metal. in this sense. With metal, you can hop in anywhere and say, I enjoy this. With jazz, it's almost always more like wine, having to find tiny things you like and developing a taste. After a while, you will notice "quotes" from other musicians that are used, for example, many sax players up through today even will quote Parker, which is why I suggest to listen to him.
Charlie Parker & Dizzy Gillespie - KoKo there is a good song. One of many greats, really.
If bebop isn't your thing and is too "chaotic", or if you do really enjoy it, then I highly recommend the whole album of Miles Davis
Kind of Blue This is an album that myself and many other jazz musicians listened to (only this album) a year usually, when they first heard it. When I first heard it, it was like experiencing new colors, and I didn't want to stop. History: this album directly followed the bebop movement of the 1940's-50's and just when people thought it couldn't get crazier, Miles knew it was time for change. So as opposed to trying to play as much over as many changes as possible, like bebop did, opting for complex harmony and rhythm, he decided to over-simplify and strictly create melody, regardless of harmony or rhythm. It was so different it skyrocketed and is often touted as the greatest album (influential) of all time.
To carry on to what Miles' work on Kind of Blue became in the modern day, mixing in the influence of crazy things like metal or rap, I'd highly recommend a few other of my living favorites:
Hiromi- a japanese pianist, almost more fun to watch than to listen to (but she plays like a beast). You can find many great videos on youtube.
Chick Corea- Spain is brilliant, his rhythm and mix of latin jazz into modern is brilliant. Here he is playing with hiromi, in one of my most favorite duets of all time.
Chick Corea & Hiromi??Marcus Miller- great bass player, he likes to take younger people that are "prodigies" and develop them. His sax player starting playing with him professionally at 13 years old and is truly an inspiration to me. If i ever met him, I would give him a hug instantly.
Brad Meldau- Possibly the best pianist alive, pushing the boundaries of jazz as we know it, I'm not sure if you'll like him. He's one that is still somewhat (a lot) over my head. Truly genius. He plays with Kurt Rosenwinkel who I , as a guitarist, can keep up with a tad bit more, but still genius.
Brad Mehldau Trio - "All The Things You Are" part 1Oscar peterson and Herb Ellis- true classics of how a small combo "should" sound. 10/10 can listen to all day and still feel good.
Joe Pass- Often touted as the greatest Jazz guitarist who ever lived. He could walk a bass line, play the chords, AND solo, all at the same time.
If you look up "all the things you are" by each one of these guys, you will see why it is difficult to define jazz as just one thing, and why it can be so overwhelming to one person. Imo a nice jazzy metal would be Animals as leaders.
Hope that's not too much, the teacher in me is coming out...