people usually get 'bored' with working out because they are working out for the wrong reasons ...
if you ask most people why they work out they will say 'to keep fit' or 'to get into shape' or 'to lose weight' and NONE of these is a specific goal and therefore provides no benchmarks and therefore no motivation.
ask yourself why you want to workout and what you would ultimately like to gain from those workouts ... try to be very specific and then examine whether those goals and the means you have chosen are the same thing.
exercise can be accomplished in many ways ... from parking your car further from work (rather than closer), to taking the stairs instead of an elevator ... to walking an extra block to have lunch ... or walking around the block after work rather than heading straight for your car etc.
going to the gym is probably one of the worst ways to develop a routine ... better to buy some used dumbells and simply do a few reps and sets when you get out of bed and are waiting for the coffee to brew ... you will then workout everyday but pick different muscles to work ... its quick, its easy, and you don't have to go anywhere.
Monday: Chest -- flat flyes; presses; flye-press combo.
Tuesday: Shoulder -- front presses, reverse presses, shrugs, laterals.
Wednesday: Back: one-arm rows -- to the chest/to the stomach
Thursday: Legs: squats, lunges
Friday: biceps curls, triceps kickbacks
toss in a few ab hollows to strengthen your abs and you are set.
mix up the routine anyway you want and like ... if you have the time, do two body parts per day.
at most, it will take you 10 minutes per day to do some exercise that will still result in some gains. no gym membership, no parking hassles, no driving around looking for excuses.