Some of mine:
AC/DC - “Thunderstruck”. When I first started, that main riff did more to improve my fretting and picking hand synchronization than anything else. Fitting that it started life as a practice lick of Angus’s. I still often play it as a warm-up.
Rodrigo y Gabriela - “Tamacun”. The whole song is a great picking exercise. It’s not terribly difficult, and it was particularly helpful to me because at around 130 bpm, its moderate tempo lied in my awkward transition zone between slow and fast picking technique. It helped me gain more control over my picking and not make it so binary between slow/fast.
Stevie Ray Vaughan - “Crossfire”. This song was both a blessing and a curse. A blessing because it did more than any other song to build my string-bending strength. A curse because it and other SRV songs resulted in my being a heavy-handed player for many years, something I had to break myself from because that hurt my playing in other non-Texas Blues areas.
Ozzy Osbourne - “Bark at the Moon”. The main riff is an all-around great rhythm picking exercise.
The Eagles - “Seven Bridges Road”. This song helped me improve my acoustic strumming skills beyond basic “Every Rose Has its Thorn” level
Megadeth - “Train of Consequences”. Learning the main riff introduced me to the joys of chucka-chucking on fully muted strings.
Guns N Roses - “Sweet Child O’ Mine”. Yeah, yeah . . .
There are a lot of others, but I’ll leave it at that as a starting point for y’all to share your own.