As a heel champion or overall champion? I'll give Ramon his dues. He was a great wrestler in Ramon mode or as Scott Hall himself. I wish WWE had him around again. These new bloods could learn from his expertise.
I'd go with Mr. Perfect or Randy Savage. Shelton Benjamin and Jeff Hardy were probably two of my favorite "modern" Interconitnetial Champions. Jericho had some great matches as champion too with guys like Benoit and Mysterio.
Pedro Morales, Don Muraco, Tito Santana, Razor Ramon, The Ultimate Warrior, Mr. Perfect, Shawn Michaels, Bret Hart, Greg Valentine, Pat Patterson, Edge, Ric Flair, Eddie Guerrero, Texas Tornado, Roddy Piper, Ricky Steamboat, Steve Austin, Booker T. The 18 WWE Hall of Famers to hold the coveted title.
As for me: Chris Jericho (for most reigns), Drew McIntyre (he was the best heel IC champion in the modern WWE era), Randy Orton (he played like his IC Title reign was the longest in WWE in a year) and The Miz (the way he doesn't want to defend the IC Title made for funny storylines where he eventually lost the belt).