"I and others" or "others and I"?

I have traditionally learned that a first-person pronoun should always come last in a list, e.g.

Bob and I found this to be interesting.

However, it sounds awkward to me when this rule is used with 'others':

A couple others and I found this to be interesting.

I would be more inclined to go with:

I and a couple others found this to be interesting.

Which sentence is (more) grammatically correct?

They are all grammatical. Whether or not you put yourself first is a matter of etiquette.

As long as you use the subject pronoun "I," and not the object pronoun "me," it's grammatical. You can put the first person pronoun either at the beginning of the sentence or after others, such as "others and I…." I and a couple of others here (ha ha) agree with putting "I" before the others. I disagree with the poster who said it's a matter of etiquette; I just think it's a matter of style and euphony. Truth be told, I like saying, "I and [so-and-so]" because it's perfectly grammatical though many people think it's not, and I like to show people it is.