Every roll is a good roll. Every gym has different people and you can find many different styles of rolling. It's normal to prefer some people to others, you have to confront all of them though. I'll describe my four favorite people's style's of rolling. These fellas make me better everyday and I also have a barrel of fun.
Ok, it's not your enemy, it's your partner. What I mean is that there are always a few people who have more or less the same level as you. You are learning the same techniques at the same time and this is great because if you can apply the technique on someone who already knows what you're trying, it's going to be easier when you do it with someone who doesn't know.
This one is my favorite one. This is the very active guy who makes you move more than anyone else. You finish breathless and wrecked. It's like he takes all your energy. You can taste your cardio with this person. Also, you will have lots of scrambles which is great because is going to make you improve your ability and end up in the best position. I always relish these rolls.
This is the safest partner. You can't be hurt by this person because he will only let you do the technique you want to do. Usually, this person is at least one belt higher than you, so, even if you complete your technique, you won't tap him. I like rolling with them because it's like a test, you have to know what to do in any position, otherwise you'll stay there like "What's next?".
Time to see how good you are. This is the toughest roll. We all know that if you're technically better than other person, you can beat them even if he's 20 kilos heavier than you. So, when you roll with a guy who puts too much pressure, you have to manage to deal with it. Sometimes it's very hard but it will help you get better. It's a necessary evil.
There are many different styles but these four are my favorites. I can learn from everyone, however there are always people you enjoy rolling more with. So, who's your favorite partner?