My workout partner, John, is a great workout partner. At the most elemental level, he shows up and always helps me have a better workout. That in itself would be enough to qualify him as one of the best I’ve had.
John is a little Italian tank with a wicked sense of humor and arms the size of Mt. Rushmore. He knows what he knows, and also knows what he doesn’t. He’s ready to learn, ready to try something new, and quick to tell me when he thinks something is ridiculous and he’s not going near it.
He’s always re
ady to say hello and be friendly with anyone. He also will not suffer fools or put up with their nonsense. Get on his wrong side and he’s done with you. Show him you’re worth some trouble and he’s as loyal as a St. Bernard.
He puts up with my mood swings and my tendency to be distracted by hotties. He can laugh at my insecurities and his own. He’s always there to give me a spot or a bit of encouragement when it’s needed. There are times I want to strangle him, but I know he could beat me to a pulp if I ever tried. He has a slightly volatile edge (that he relishes.)
A great workout partner should have these qualities of consistency and support. The trick is to find someone who matches your intensity level and has the same basic goals. 
It’s not mandatory to have someone with the same strength level, but it can be a real plus since this means you have to add and remove weights a lot less often during the workout.
So when you’re looking for a workout partner, find someone who works hard but doesn’t take it all too seriously. Find someone who knows a lot, but doesn’t think they know everything. And find someone who you enjoy being around and can imagine seeing most every day.  In other words, find someone like John Passarella.