ezel is newer. it has only one season now. aşk-ı memnu is finished, i think it has 3 seasons. I watched aşk-ı memnu from time to time only, it is a typical love story soap opera. A rich man marries a young and beautiful woman. His young and handsome nephew also lives with them so soon his wife and nephew fall in love and they have a secret affair blah blah.
Ezel is more adventerous, it is about a man who changes his appearance and comes back to get a revenge. They say it resembles "the count of monte cristo" but actually i don´t know this story. Anyway, I think it is one of the best series made in Turkey upto now.
I agree for your opinion .