"Turtle Boy vs. Darkseid" from Countdown to Final Crisis #2/Week 50 (DC, 2008) by Paul Dini, Sean McKeever, Keith Giffen and Scott Kolins
I promise this will be the only splash from a book with Countdown in the title. I also don't particularly want to discuss how terrible, messy and in the end IRRELEVANT the weekly Countdown series was . It didn't so much lead up to Final Crisis as it contradicted it. So let's bask in the insanity of the above match-up between a giant, mutated Jimmy Olsen and an equally Godzilla-sized Darkseid. Because Countdown had this at least.