My go-to when I have a bunch of people coming over:
Pot Roast w/ baby veggies:
1 roast (beef or pork, doesn't matter)
small red/yellow potatoes
celery (cut into sticks)
onion (cut into chunks)
Put everything in your slow cooker and add a ton of salt and pepper (and whatever else you'd like- sometimes I add a touch of garlic powder). Top with beef stock or broth. I usually use one or two cans, and then fill the rest of the crock pot with water. You can also add a little bit of worcestshire (am I spelling that right?? lol) if you want. Cook on low for up to 10 hours.
I usually make rice or mashed potatoes with this meal. Rice is easier, obviously, but the mashed potatoes really hit the spot. Add some bread rolls and you've got a super yummy meal.