Hotel Eastlund is literally across the street from the convention center and about a 3-4 block walk to The Moda Center. It opened a couple of years ago after extensive remodeling of the property, and is very nice. It has a rooftop restaurant and a coffee/breakfast shop on site. It's easily accessible from the TriMet train (literally walk onto the train platform from the airport, exit at the convention center), which also means it's a couple of stops on the train if you feel like exploring downtown.
I've stayed there twice for Rose City Comic Con at the convention center, and I would highly recommend it. I wouldn't say the area near the arena is any worse than the area near the Saddledome - probably better, tbh.