We usually stay at Ocean Reef resort. It seems to be one of the cheaper oceanfront resorts, and has 2 queen beds instead of doubles, which is always nice. It has an outdoor pool, indoor pool, hot tubs, lazy river, & a kids play area. It's also right on the beach, but the parking lot is across the street (which I'm pretty sure is common in that area, some have parking under the hotel, but it didn't seem like many of them we saw did). We had a room with a kitchenette, so we were able to keep sandwiches, drinks, and other snacks in the room for when we got back from a long day on the beach. We thought it was a nice room the price, it was clean too. The elevators were super fast as well, which we really liked, considering we were on the 15th floor. They also have guest laundry on the 2nd floor, which was convenient for us, since we were staying there for quite a few days and needed to be able to wash bathing suits, shorts, & tshirts.
http://www.oceanreefmyrtlebeach.com/
However, if your kids are young, I definitely would not recommend staying in south Myrtle Beach, mainly know as the "Grand Strand" area. It's usually loud down there until around 4 maybe even 5 in the morning. We did like the fact though that we could drive down to that area of Myrtle Beach because there was always something going on, but then we could go back to the hotel where it was nice and quiet, and we were able to get a good nights sleep.
OT - But if your family wants some souvenirs while you're there, you should definitely check out the Gay Dolphin, it seems like they have everything you could ever want to take home!