Parc Outremont is great for running, lounging, picnic-ing, and playing frisbee. I remember running laps around this parc for PE, hanging out in the parc during breaks, eating outside with family. It's a nice friendly parc. It is very family oriented so no alcohol is allowed, also it "closes" at a certain time so you can't really loiter around after hours.
It's a great, green and relaxing parc. There's a pond and a kids playground.