That would entirely depend on where
you want to start really... you say you're too 'pretentious' (your word!) to read fantasy/sci-fi, what honestly? I mean I'd understand if you were talking about the likes of Robin Hobb, Terry Goodkind, or George RR Martin (apologies to any fans... we can take it outside if you like?
), but Moorcock is such a wide ranging talent, writing over such a long time, I think he's probably written something for just about everyone in his lifetime, whatever your tastes.
Some of his work is definitely immature, but, he started writing very young, some of it is definitely repetitive andcould be considered 'weak', but, he was making a living as a pulp author churning out 'fashionable' material for a long time, and has admitted himself it wasn't always 'great fiction'. Some of his works have been republished several times under slightly different names, some identical sections appear in different works, he describes his writing as 'chaotic' and some if it certainly is - infuriatingly so, but he pretty much invented the Warhammer definition of 'Chaos' (at least as adopted by Bryan Ansell). However, depending on your tastes, you may find some of his work very good indeed - I do, and I can be pretentious too (according to the wife anyway). All I can say is, if you try something he's written and don't like it, try something else, and you might just really enjoy it.
Personal Favourites:
The Warlord of the Air Trilogy AKA The Oswald Bastable Trilogy AKA The Nomad of Time Trilogy (very Steampunk alternate realities, with more than a hats off to HG Wells)
Hawkmoon AKA the Kamarg Tetralogy - The Jewel in the Skull, The Mad God's Amulet, The Sword of the Dawn, The Runestaff (a very fantasy take on a 'Dark Future' with a LOT of Moorcock's famous dark humour, there is a second Hawkmoon series as well, not so good IMO. I think there was a 70's band called 'Hawkmoon' as well, in which Moorcock played? I may be confused, that was before my time...)
Corum AKA the Corum Trilogy - The Knight of Swords, Queen of Swords, King of Swords (actually two separate trilogies about the central character Corum, both good, but the first is the best IMO, this is where we first see a lot of the elements of classic Warhammer - Elves, Chaos, Chaos Attributes etc...)
Michael Kane AKA Martian Triology - City of the Beast, Lord of the Spiders, Masters of the Pit (a Martian series very much after the style of ER Burroughs and 'John Carter: Warlord of Mars', classic SciFi/Fanasy)
Sojan the Swoirdsman (Moorcock's 'tribute' to RE Howard's Conan)
The War Hound and the World's Pain (as someone mentioned above, quite possibly Moorcock's most literary work, and a real stand alone gem, set in the 30 Years War Rhineland, but with strong fantasy elements, an absolute classic)
So, a real mix of stuff, a lot of it totally original and a lot of it based on the work of other authors, take your pick!