Are you making the most of your workout time? If you dread your exercise routine or do the same thing, day after day, then your regimen might need a shakeup. Getting started is half the battle, so why not start with something you like? Kickstart a good workout with whatever gets you going. If you like bicep curls, start with weights. Enjoy your cardio? Hit the machines first. It'll put you in a good mood and help you exert more effort in the less-pleasant parts of your workout.
Find your peak time at the gym - it's no fun having to wait around for your favorite machine or having to settle for the elliptical trainer when you really enjoy the treadmill for your cardio. Identify the down times at your gym and try to go then so that you get your pick of activities. If you do have to wait, then use your down time on stretching. Sneak in lunges, squats or crunches while you wait. Want to attempt a class you've never tried before?
Spy before you try. Don't waste your time on a class that's not for you. Arrive at the gym a few minutes after the class gets going, then watch for five or 10 minutes. You'll get a sense of whether or not the class is for you without wasting an hour or more in a class that you don't love.
Don't simply trudge through your cardio workout. Look at those around you. Find someone who's obviously working hard and try to match or exceed their pace. Just be sure not to push yourself beyond your limits.