Which is more common - 'the most' or 'most'?
I did a few searches in Google books to see if I could find a pattern. It seems like more hits are found when the article is omitted rather than added. Here are my results (all searches were done "in quotes"):
Things I love most: 8310 results
Things I love the most: 1570Things I hate most: 2060
Things I hate the most: 195Things that bother me most: 859
Things that bother me the most: 207Things I like best: 25,000
Things I like the best: 295Things I do best: 6890
Things I do the best: 1870
Given that a pattern is emerging, the next question would be: Why?
I remember one tip for effective writing: eliminate extraneous words. That admonition is found all over the web. For example, such words are called flab in this blog; the same exhortation is buried into Tip #9 of this writer's guide:
9) Write more than one draft of your essay. Great writing comes from revision. Eliminate extraneous words and phrases. After you revise, be sure to proofread and spell-check your work. Proof-reading is not the same as revising!
I'm guessing that it's often omitted because it's unnecessary. Which leads me to the last pair of queries I ran (not in Google books, but just as a Google web search):
Eliminate extraneous words: 5890
Eliminate the extraneous words: 68
There may be a slight difference in meaning. It would be somewhat awkward to omit "the" in the following, because we are referring to someone/something mentioned previously:
What I loved the most [about her] was her eyes.
On the other hand "the" would be unnecessary in the following, because we are not referring to any context much more specific than life in general:
What I loved most [of all] was being able to play in the woods as a child.
But one might say:
What I loved the most [about my childhood] was being able to play in the woods.
I would conclude that an indefinite "most" is slightly more general and less dependent on context than "the most." With the latter, there is usually some antecedent to answer "the most of what?"
If your question is about frequency, in both the Corpus of Contemporary English and the British National Corpus there are three times as many records for most as for the most.