alcudia in north Mallorca is cheap, family friendly, has a waterpark, gokart, beach with activities etc and no clubs so the rowdy crowds of magaluf etc wont be annoying you. great if you ahve kids upto 12 or 13 i'd say,
above that palma further south on the island is probably a better choice,
Imo, tenerife is worth the extra coin but stay in los christianos not playa-de-las-americas, its gone downhill in recent years and LC is a nicer resort, the waterparks are just a bus ride from both.