It's interesting to hear more landlords' perspectives on what makes a "good" tenant. We've been in this apartment for five years, and the landlord always mentions how happy he is to have us as tenants.
We haven't improved the place, but we do take care of little things ourselves and tell him when a repair that we can't/shouldn't do isn't important to us. For example, the kitchen tap drips cold water. Fixing it would require replacing the faucet setup entirely. We told him the problem exists but, as water is part of rent, we don't care when it gets fixed, if ever. So, he will probably wait until he needs to cut off water to the house (including his family and another rental unit) for other reasons and do the fix then.
We don't fuss when his kids are learning to play the violin and the saxophone downstairs. :)
Maybe it is just that we are better in comparison to the terrible tenants. He recently had to evict a tenant who hadn't paid rent for five months. When she left, he discovered that in the no-pets apartment she had been keeping two cats with no litterbox. Now he is stuck replacing carpet that should have lasted a few years more, doing extensive cleaning, and calling authorities about the poor cats and the ex-tenant's children who had to live in that situation. He won't be getting any back rent, as she quit her job and is now on disability.