Buy my first bmw, what to buy? E30? E36? or smothing else??

I want to buy my first BMW. An older BMW, preferably a 4 cylinder and something I can pick up for fair inexpensively.
I do enjoy working on cars and would like a more practical and fuel efficient car than what I have now
but at the same time something with good driving dynamics that is enjoyable

Buy my first bmw, what to buy? E30? E36? or smothing else??