I have a clock radio that I sometimes set, but usually it’s my husband.
One morning, he woke me up and I hit him on the head - he asked me why the hell I did that - I told him “Snooze Alarm.” 
I nominate this as Post of the Day!
I’ve got a primitive clock radio, of the sort that you could have gotten for ~$10 anytime in the past 30 years. It’s set to Annapolis indie rock station WRNR, except at those times when the cleaning woman has accidentally moved the dial.
My Fitbit One, slipped into a wristband and held against the inside of my left wrist. It vibrates to wake me up, so I can get up earlier and not disturb my husband’s sleep. These days, he’s getting up earlier than I am, but I still prefer this to a sound-based alarm.
Moving over to MPSIMS, like you asked.
Thank you.
We have skylights in our upstairs bedroom which is where we have been sleeping.
My wife is not disturbed by the light, but I am. So, the sun is my rooster.
Fortunately, I work from home, so I don’t have a regular schedule.
Great topic, by the way. 
Did you ever wonder why they started cropping Dobie ears? I’m pretty sure it’s because they make a Christless awful noise being deliberately and repeatedly flapped, ten minutes before the alarm goes off.
When I have to get up for work or whatever, an alarm clock. The kind that plugs into the wall, not a cell phone.
When I have the option of sleeping in, it’s just whenever my body decides that it’s had enough sleep.
These days it’s the sun. Later in the year, the dog will start nudging me towards breakfast before the sun comes up, but for now sunrise does it.
I love 103.1 - that and crabcakes are the two things I miss most from Maryland. Thanks for the reminder - listening to their online stream now.
I’m convinced one of our basenjis shakes her head just to make a noise and get attention, sometimes in the middle of the night. Even the prick-eared buggers can make a loud plub-blub-blub sound if they want to.
I’m retired so generally I sleep until I’ve had enough sleep. On those occasions when I have to get up for some reason to do something, I have an alarm clock that makes a buzzing/ringing noise.
Weekdays it’s some generic iPhone ringtone. On the weekends, it’s the first flights going overhead at 6:30.
Bladder. The cats are polite because breakfast will be very late if they squawk…
The sound of aClown Loach snapping her dental plates together to crush Malaysian Trumpet Snails. Or the dog if he needs to pee before the light hits the aquarium.
If that doesn’t do it, then the cd player will play the Ultimate Wake Up Song. (Kila - Handel’s Fantasy). It’s the Ultimate because it starts as a sweet violin intro, then builds into a spirited reel, and ends with three brothers on a stage basically daring each other to keep up. So it gives you the option to wake up gracefully, but if you let it go too long, by the end, your blood WILL be pumping. LOL!
To get the full effect you have to play it on a system with really good base. Towards the end Ronan is banding on a Japanese drum taller than he is. That level of sound is completely lost on my computer speakers.
Any number of things. I don’t have a set schedule, so if i manage to sleep through one thing, something else will do it.
There’s a bird outside that starts singing at precisely 5:30 every morning. He’s loud and likes the tree by our bedroom window.
My cat learned a long time ago that irritating me is the best way to get me up. So she does something bad. Knocks something over. Finds something plastic to chew on so I hear that crinkle sound of celophane. She’ll even go into the bathroom and paw at cabinet doors so we hear the bang as they close. She knows we don’t want her in there. Lately she crawls up onto my pillow and nonchalantly sits on my hair (ow!).
My dogs start whining a high pitched crack-the-windows wail for breakfast in the kitchen. As if they’ll never be fed again.
My husband sleeps like the dead and doesn’t wake to his own alarm, so he says. I think he’s just too lazy to hit snooze. I have to nudge him and say “hon”, then he rolls over and hits snooze. I swear he will allow his alarm to beep for a half hour or more. He also likes to snooze through 2 whole hours of alarms! Ug! I just recently got him to reduce it to 1 hour. I hate that noise! One beep and my hand shoots out to the button!
Damn… Camera and lens envy!
In decreasing order
Habit
Bladder
Dog shaking and wagging. She seldom nudges me unless it is late, and she prefers to nudge my wife
Clock radio set to KQED
Either I’ve gotta pee, or one of my cats is banging on the blinds to wake me up.
Light in the room, backed up by three itchy, hungry, floppy-eared dogs.