I don't like onions in my meatloaf either, although I do sometimes use the old Ann Landers Meatloaf with onion soup mix.
I make a good meatloaf using spaghetti sauce for seasoning.
Italian Meatloaf
3 lb ground chuck
2 cups spaghetti sauce, divided
1-1/2 sleeves crushed saltines
2 eggs, lightly beaten
1 tbl Worchestershire sauce
1 tsp salt
1/2 tsp pepper
Reserve 1/2 cup spaghetti sauce. In large bowl, mix remaining ingredients thoroughly. Place in large casserole dish and pat firmly into a round loaf.
Cover and cook in microwave on med-high for 15 minutes. Remove lid, discard any drippings, and spread remaing sauce on top of loaf. Cook, uncoverd, on high for 10 more minutes. Check temperature with meat thermometer if in doubt. Tent with foil and let stand 10 minutes.
You can also use the traditional method of cooking at 350 degrees in the oven, covered for 45 minutes, then top with sauce and bake uncovered for the last 15 minutes. (This cooking time is approximate...depends on how thick your loaf is...use your trusty meat thermometer.) Again, let it stand 10 minutes or so.
If you do cook your meatloaf in the oven, you may as well throw in some baked potatoes or a dish of macaroni while you have the stove on.
Whatever recipe you use, just remember not to overcook the meat. Your meatloaf will continue to cook after you get it out, and you don't want it to be dry.