I've always wanted to visit Jinan. ok I always want to visit Jinan. ok I'd always wanted to visit Jinan. ok I'v always been wanting to visit Jinan. X >>I have always been keen (adjective ) to visit Jinan

I've always wanted to visit Jinan. - Is correct. Present Perfect (until now). I always wanted to visit Jinan. - Is correct. Past Simple (in the past). I'd always wanted to visit Jinan. Grammatically incorrect. I'v always been wanting to visit Jinan. - Grammatically incorrect. "Want" is not normally used in the Present Continuous.