Lake Nona area- nice and very close to MCO (10 mins or less)
Lake Mary/Heathrow area- also nice but 35 minutes on sr417 from MCO (toll road ~$4 each way) west of I4 is nice, closer you get to SFB the more you have to pay attention.
Merritt Island/Cocoa Beach/Viera- nice area, about 45-60 minutes away but lower COL and nice area. About $2.50 each way in tolls. IMO great for if you have a family, probably gonna get bored if you are single
lived in Lake Mary/Sanford and Merritt Island/Viera area and have very few complaints about either. Would definitely lean toward lake Mary/Heathrow vs Sanford though.
best of luck, I love central FL.