+1000 to learning Death....especially Symbolic! I learned almost all of Sound of Perseverance, however I took the easy way out by using tab My chops def improved drastically after that! RIP Chuck
The one thing that most guitarists neglect to develop is any sense of rhythm.
Try and play some Stevie Wonder, bebop heads, Charlie Parker, Tower of Power.
Cover that. I'm sure it will utterly kick your ass. The worst part is when shred guitarists take up that challenge, play the heads, and don't realize how rhythmically bad their performance is. Don't be one of those people.