Dumbells are great. You can work every muscle group and they are very effective. In addition, they're small, so if you don't have much space, they're perfect. There are some variations of selectorized dumbells. That way you have an entire dumbell series, but only take up the space required by a single pair. With a set of those and an adjustable, incline bench, there's almost nothing you can't do.
BFL