Swimming (when I've done it regularly) before work.
Weights, rowing, running, cycling, yoga, BJJ after work.
Bodyweight exercises throughout the workday (aiming for about 5 minutes every hour as part of my "get up and stretch" routine).
I am not limber in the morning and find swimming is the only exercise I can do that doesn't cause me more problems when done in the morning (after some stretching). Everything else, after work. For cycling, because I don't want a time limit on my rides. For everything else, because I'm finally loose enough to actually do the exercises without risk of injury.