For variety of keyboard layouts, I like Kii the most. I personally like the landscape 13-key split layout as I can type with fewer errors on this layout. The auto-correct and text prediction is not as good as other keyboards I have tried. It also has gesture typing where you can slider your finger across the keyboard without lifting it off the screen. The gesture typing is OK and not as good as Swype.
For the best text prediction and auto correction, it's SwiftKey. I would be using this if it had a better keyboard layout. I keep hitting the space bar and shift key by accident on this keyboard and make many more keying errors. If you find this keyboard and its layouts comfortable to type on, I would highly recommend this. Gesture typing is supported and is OK.
For the best gesture typing experience, go with Swype. No other keyboard I have used is better for gesture typing than Swype. It has a great feature where if you drag your finger above the keyboard as you gesture type, it will capitalise the letter. It makes it easy to capitalise a word without having to hit the shift key. Auto-correct and text prediction is also very good and almost as good as Swiftkey. It has some more layouts in the recent update including a split landscape keyboard. The latest update has some lag when typing in landscape.