I thought G.I. Joe for what it is: an action movie. If you want non cliche storyline and excellent acting, then this movie is not for you. But, if you're willing to put that stuff aside and in turn receive over the top action scenes that will have you grinning from ear to ear, I would definitely recommend it.
That's exactly how I felt after seeing Transformers 2. I never played with G.I. Joe toys when I was a kid, but I had a ton of Transformers and as ridiculous as Transformers 2's plot was, watching it on IMAX made me feel like I was 7 years old again. It felt like watching an episode from the original cartoon series, only with Megan Fox and awesome CGI. I could see how someone who was a die-hard G.I. Joe fan as a kid would feel similarly about this movie.