I grew up reading only Marvel, now I'm trying to get into DC a bit and I'm wondering what the great runs of Justice League were?

I've read the JLA page here and the major story arcs sections seems overly focused on stuff that happened the last 5-10 years which is understandable, but I'm mainly interested in older stuff (pre 1990) or really anything as long as it's good.

There's some good Pre-Crisis stuff from the Justice League, but it's not that great, and most certainly not the first JLA-related stuff I would read. Anyway, these are some of my favourite Justice League versions/runs. All of these are very new reader friendly (as long as you start from the beggining), but Justice League International/Europe is a pretty different League, so I wouldn't start with that one. New 52 Justice League is probably the most new reader friendly one:

Long Story Short

• JLA: Year One
• JLA: Incarnations

Justice League International/Europe

• Justice League International: Volume 1
• Justice League International: Volume 2
• Justice League International: Volume 3
• Justice League International: Volume 4
• Justice League International: Volume 5
• Justice League International: Volume 6
• Formerly Known as the Justice League
• I Can't Believe It's Not The Justice League

JLA

• JLA: A Midsummer's Nightmare
• JLA: New World Order
• JLA: American Dreams
• JLA: Rock of Ages
• JLA: Strength in Numbers
• JLA: Justice For All
• JLA: World War III
• JLA: Tower of Babel
• JLA: Divided We Fall
• JLA: Terror Incognita
• JLA: Golden Perfect
• JLA: The Obsidian Age (Book 1)
• JLA: The Obsidian Age (Book 2)
• JLA: Rules of Engagement
• JLA: Trial By Fire
• JLA: Crisis of Conscience (read Identity Crisis first)

Justice League (New 52)

• Origin (1-6)
• The Villain's Journey (7-12)

Elseworlds

• JLA: The Nail
• JLA: Another Nail
• JLA: Riddle of the Beast