Non flip phone is better.Flip phones have a higher chances of getting damaged due to the two parts which is connected by ribbon that has a higher chances of breaking.
This depends largely on what you prefer. Flip phone are good if you do not want to bother with the key locks to keep from pushing buttons while the phone is in your pocket or purse.
Well a flip phone is good if you carry your phone in your pocket a lot and have limited space. They are typically smaller and you less of accidentally dialing.
Both are considered to be good choices. With the flip phone you don't have to worry about your phone becoming damaged. And a non flip phone is accessible.