What is the best answer to this question when applying for a job: What is your expected annual base salary (excluding allowances, bonuses or benefits?

The best way to answer to this question is as Competitive salary as per the industry standards.

To be more specific to this question, it is always good to do a market study for the salaries based on the position you applied for.

You shall be careful while answering to this question, Make sure you don't ask something which is very high from the average salary for that position which may lead the recruiters to reject you as they always look out for the cost effective candidates.

It's depends upon the position applied for, market rate and company policy  ( employer ).

I fully agree with the answers been added by EXPERTS.................Thanks.

The highest number you can bring yourself to say without embarrassment.   You never get more than you ask for.  

The truth, of course...............