So to get consistent traffic, the best option is always the major search engines like Google, Yahoo! and MSN. And even out of these search engines, the most preferred search engine is of course Google.com
So if you want to know, exactly which keyword to use, whether to use American English or UK English (as different people use different spellings like colours or colors), visit the link below to get all your answers:
(The tool helps people to calculate the worth of any word, by it's popularity in the global searches, but you can use it in another way too, that means, you can use those words which are mostly searched for, in your articles and posts.)
Type the words one-by-one then enter the captcha and click on get keyword ideas
So for the words entered by you, now the results will be displayed, along with similar phrases, and you will see how many people have searched for those phrases in the recent past.
In the Approx search volume(for last month), the numbers displayed tells you the approximate number of search queries matching your keywords that were performed on Google and the search network in the previous calendar month. This number is specific to your targeted country and language as well as your selection from the Match Type drop-down menu.
Another way to get huge traffic, is the utilization of Hot Trends tool, given by Google Labs, which displays the 100 Most searched words in Google by the people of United States.
Google Hot Trends (Although limited to US searches only)
By having a look at that page, you can see what word is being searched the most in the last 1 or 2 hours, and then quickly find out why, then present the whole story in a more better way so as to attract more people. And as the story behind the keyword spreads more, & so even more number of people will start searching for it.
The above mentioned tool is actually a part of "Google Zeitgeist", which means "the spirit of the times", and Google reveals this spirit through the aggregation of millions of search queries we receive every day. Several tools of Google give insight into global, regional, past and present search trends. These tools are available for you to play with, explore, and learn from. Use them for everything from business research to trivia answers.