IndeedAccepted the SCW does not interest you, but to describe it as a proxy war is, I feel, incorrect. The war may have been sustained by support from Germany, Italy and Russia, but they had no influence on the causes or prosecution of the war. The interference of the Soviets in the Republic's political composition, was however a contributing factor in its defeat.
Other than that, I'll say the Spanish Civil War. It's interesting how it turned out to be a proxy war between communism and international fascism.
Well, the communists had their role in the war, but despite their efforts they didn't reach an hegemonic place in the republican side. Even in the 1939 besieged Madrid they tried a takeover that was quickly counterbalanced by the socialist anarchist and republican factions. In the 1936 elections the Communist Party of Spain had only the 5% of the votes. Although the Republic recieved some interested support from the soviets, they didn't control the Spanish Republic. As Jim has said, the Stalinist intervention, that wasn't for free, was only a source of instability and tensions among the republican ranges.
In short, all the republicans, socialists, trotskysts and anarchysts that fought against the fascists won't agree with you.
Of course, I conseder the SCW the most interesintg conflict of the XXth century, but my opinion is baised since I live in its consequences.
Cheers