Here's a type of cover you won't see very often, as it is not very easy to work the title into a word balloon. Let's look at a few examples:
The first one that comes to mind for me is Peter Parker, the Spectacular Spider-Man #59 (October, 1981) as I bought it off the spinner rack. While the character poses on the cover seem a bit awkward and the colour scheme is drab, the design and execution of the word balloon is brilliant. This is a perfect example of this type of cover. Also a good one for fans of the Gibbons fans out there. You are out there, aren't you?
I only saw the cover to Superman #11 (November, 1987) for the first time a few weeks ago and it made me smile. This is a terrific way to incorporate the Superman logo into a word balloon. I love the fact that the balloon cannot contain the logo. I also love that Lois is so triumphantly 80s. Great stuff, but I kind of wish they had a Mxyzptlk font to use for our little imp.
The cover to Weird Western Tales #44 (Jan-Feb, 1979) is in a bit of a grey area, as Scalphunter is not technically the name of the series. The thing is, this is my blog so I can make up the rules so I declare that this one qualifies. In any event, it is very inventive. It would also qualified as a 'hanging from the feet' cover and 'racist sheriff' cover.
Let's leave off with Archie... Archie Andrews. Where Are You? #3 (September, 1977). I could have chose a lot of covers from this series, as they used the Word Balloon technique for the first 20 issues. In fact, everyone from Veronica to Dilton asked this question on various covers. Does anyone know of the earliest example of this type of cover?