For me it's Internazionale,Dinamo Zagreb and Real Madrid.
and I am a free man who doesnt give a damn so dont bother.I'll tell you why you can't support/love your rivals.
Imagine you're with your wife and you love her. Her rival chic, one she hates......you can't like her. Ideally you should hate her despite the fact that she isn't particularly mean to you.
Sports is essentially two entities competing against each other. If you're a fan you have to support one of them. You can't support both. Otherwise just call yourself a neutral who doesn't support anyone.
Analogy: It's like you're gay or asexual and aren't attracted to any of the gals.