I've never been a Transformers fan, didn't see the original cartoons as they weren't much of a thing here in Europe back then, but I thought Transformers 1 was decent despite the obvious flaws (mostly Shia, Megan Fox scenes where she is doing anything but showing her ass, and the terrible humor).
I absolutely loathed Transformers 2, which destroyed any expectations I could have had for Transformers 3. Surprisingly, I ended up disliking Transformers 3 anyway despite the low expectations.
So I had no intention to go see Transformers 4 but my wife decided otherwise because she has the hots for big robots...
Anyway, long story short, I was dragged to the theater, I expected to be once again utterly disgusted by this movie, and it was bad yes but it was better than 2 and 3. Not as "fresh" as 1 obviously, I think the design of the robots is very uninspired now but this movie had a lot less dumb humor (still some but funny enough the comic relief characters tend to die immediately in this movie).
Mark Whalberg was leaps and bounds better than Shia, and I thought he was not annoying at all which is quite a feat when you're in a Bay movie. Even the daughter and the boyfriend seemingly had some use despite a couple bad scenes.
The main issue with the movie was the plot that made absolutely no sense and went all over the place, and the movie itself was too long.
I now rank these movies as 1-4-3-. Because 2 doesn't exist. I can't say I really recommend this movie because it was not good by any means, but it was not as bad as I'd figured by reading the comments here so make up your own mind.