Heart: I've only made heart once, but I enjoyed it. It has a nice beefy flavor. The sucky thing about working with heart is that you're supposed to trim off all of the membrane from the inside and outside. Use a very sharp knife or else you won't get anywhere. Once trimmed, either braise or pressure-braise it. Putting bone broth to good use here is recommended. ADDENDUM: some PHers on another thread recommended high heat grilling to rare for heart meat as well.
Liver: If it's a thick slice, cook it to no more than medium. Grassfed liver is less fatty than grain fed, so it is very easy to cook to tough. Rare purple insides shouldn't deter you here, though it feels a bit odd. If you can slice it yourself, slice it very thin and pan fry. If your liver is frozen, put it in a skillet on top of thinly sliced onions and some butter, and bake it at 350F until it's no longer purple inside (will be slightly pink), turning once.
Filet: High heat, short time. Any more than rare is a waste, because it comes out mealy. I wouldn't bother trying to wrap it in bacon, either, since the steak will overcook before the bacon is done.
Ribeyes: My favorite, favorite, favorite cut. Warm in a low 200-degree-F oven until it feels warm all the way through, then grill it or sear it on cast iron until it has a nice brown crust. The interior will be rare, and it will be delicious.
Skirt: Fajita meat. Season well, grill to medium or medium well, then slice against the grain to make short fibers. Serve with grilled veg of your choice, guac, and whatever dairy you're comfortable with.
Ribs: barbecue nirvana. Less difficult than brisket but very rewarding. The easy thing to do is hot smoke them for an hour or two, cook low and slow (about 225F) for three hours minus the amount of time you spent smoking, then you have a choice. You can wrap them in foil and leave them on the grill for four or so more hours until the bone pulls out easily, or you can transfer them to a pan of braising liquid and throw them in a low oven for the same amount of time.
Chuck roast: pot roast. Sear the outside, then put in a slow cooker with wine, water, and veggies until it falls apart with a fork. You can also use it for stew meat. Chuck is a great choice for making various beef dishes, as it can be cooked through without becoming shoe leather.
Top round: roast beef. Sear the outside, then cook in a medium oven (375F) until the internal temp is 130F. ADDENDUM: Cook's Illustrated now recommends a very low oven (225F) and turning the oven off once the roast is near done (115-120 internal temp) to make the best roast from round. I've tried it without turning the oven off and even then it's excellent.
Marrow bones: 400F oven until cooked through, serve with some roasted potatoes. Save the bones for bone broth.
Kidneys: make stew with some of the sirloin tips or chuck; beef and kidney stew is delicious. You have to trim the fibrous bits from the middle of the kidney before you can use it.
Steak tips: marinate these however you like, then grill or pan sear to taste. They're still steak, so the same basic ideas apply.
