I like his early stuff -- a lot. His early stuff was the best. Listen closely to the guitar on White Room. The part where the waa-waaing guitar transforms into a warbling flute. About 2:40. I still get goose bumps.
He was a pioneer, like Hendrix.
Unfortunately, I haven't cared for his products since Derek and the Dominoes. Maybe that's when he got sober.
But the truly influential thing was the sound of his guitar, his tone. Everyone was playing Rickenbacher and Gretsch hollow body jangly guitars or the new Fender Teles and Strats. Clapton grabbed an old '59 or '60 Les Paul (the model at that time was out of production because nobody wanted them anymore) and plugged it into an amp from a new boutique amp company in London called Marshall and he turned it up to eleven. The sound he got was the sound everyone after that wanted. All those guys in the '60s and '70s playing Les Pauls into Marshall stacks took their lead from Clapton. He wrote the book on the sound of rock from 1966 on.