To compare 9.11 and 9.9, we can compare the digits in each place value.
Both numbers have the same value in the ones place, which is 9.
The tenths place of 9.11 is 1. The tenths place of 9.9 is 9.
Since 9 > 1, we have 9.9 > 9.11.
Alternatively, we can rewrite 9.9 as 9.90. Now we are comparing 9.11 and 9.90.
The ones digit is the same for both numbers, which is 9.
The tenths digit for 9.11 is 1. The tenths digit for 9.90 is 9.
Since 9 > 1, we have 9.90 > 9.11, which means 9.9 > 9.11.

Final Answer: The final answer is $\boxed{9.9}$
