i have had every type of case on my phones and each one has it's pros and cons. i put together a little guide so here is my 2
c on cases
1. Clear bendy cases:

cheapest of the bunch. like a condom for your phone. easy to put on, easy to remove. these are a dime a dozen. might protect from drops up to a few feet. tend to yellow over time. the sides stop hugging the phone over time and start to droop. also dust/dirt collect underneath and since it's clear, it shows.
2. clear back with frame (can either be soft tpu backing or hard polycarbonate aka "PC")

framed cases (usually PC) are better than #1 because they hold the case onto the phone. cheaper cases will still yellow so think about going with a reputable brand or check reviews. dust also somehow manages to find its way under the case and because it's clear, it shows. because the back of the phone is glass (or some version of it) i recommend covering with a screen protector. cases rub against the phone over time and create little dull rub marks (dust/dirt worsens the effect).
3. one layer cases

the most abundant type with the most variety. similar to #1. can be flimsy or rigid. easy to remove. protection varies, usually mild to moderate.
4. two layer cases

my favorite type. like #2, it has a secondary layer or frame that holds everything together. this type also comes in a wide variety. protection is moderate to high but it can be thicker. also more cumbersome to remove, requiring a method of removal that, if not followed would break the case.
5. leather cases

look great but are susceptible to wearing down during normal wear and tear. the leather tends to soften and become fuzzy. also stain easily. lifespan on the short side compared to the rest of the cases.
6. wallet cases

i particularly don't like these cases but it might be for some. when i get my phone out, i just want my phone, not my entire wallet. also don't want to flash all my cards when i am on the phone.
7. indestructible cases

these turn your phone into a nokia brick. you can cause great injury if you throw this at someone. highest protection at the cost of being really thick it probably needs a belt clip or holster. some make phone waterproof, with the s7 it's moot.
8. wood cases (none available yet)

these are usually found at county fairs or malls that specialize in custom engraving designs on them. they are usually smooth. protection is moderate to high as they are usually thick. but may crack if dropped the wrong way. fit is snug and removing routinely is impossible without fear of scratching the phone. short lifespan compared to the rest of cases. can also stain or retain scratch marks.
note:
- the more texture you have on the case, the more dirt/lint that collects in between the design
- certain cases/bumpers/frames especially made out of metal may interfere with reception.
- think twice about getting a credit card case if you are going to be using wireless charging.
- tempered glass/screen protection for the front AND back is always a good idea even if you have a case.
- skins/wraps/decals/stickers may look great but do diddly squat for protection and can be difficult to remove. initially it is easy but over time the adhesive bakes onto the phone. luckily the phone is waterproof but tread with caution and read reviews for these.
- having no case is ideal because the phone is so beautiful, but it requires the utmost care and attention. probably it's own pocket.
sorry for the long post
