Bands with great second albums

Cheap Trick: Heaven Tonight

Yes- Indeed, Fragile is great... But their second album Time and a Word is a strong album. I really like their their first four, with Close to the Edge next. I am always engaged by their first two, and Time and a Word early press LP sounds darned good. Agree on Joni: Clouds, but I feel it is sandwiched between two better albums. 

The Cleveland Symphony .

Here are some more esoteric choices:

Gentle Giant, Acquiring the Taste
Ambrosia, Somewhere I've Never Traveled
PFM, Per un amico
Iceberg, Coses Nostres

Great times back in the day!

Moody Blues!!!