1. iOS/ iPhone
1.1. Pros:
1.1.1. Extremely Stable
1.1.2. Very User Friendly
1.2. Cons:
1.2.1. Highly Proprietary
1.2.2. Not locally repairable
2. Windows 7 Mobile
2.1. Pros:
2.1.1. Highly Compatible with Microsoft products
2.1.2. Familiar interface for existing Windows users
2.2. Cons:
2.2.1. It's the lack of basic features such as multitasking and copy-paste for text that really makes things difficult for the users.
2.2.2. There are some things that aren't immediately apparent, such as the way you have to press and hold on certain items to display additional options.
3. Siri
3.1. Pros:
3.1.1. 1
3.1.2. 2
3.2. Cons:
3.2.1. 1
3.2.2. 2
4. Android
4.1. Pros:
4.1.1. Has two cameras, front and back/And has flash
4.1.2. Adaptable/Comparable to variety of devices/platforms
4.2. Cons:
4.2.1. HTC sense crashes constantly
4.2.2. Market is slow
5. Ice Cream
5.1. Pros:
5.1.1. Wide variety of hardware support
5.1.2. Google
5.2. Cons:
5.2.1. No wireless cloud backup
5.2.2. 2