D&D General did giants ever get the spotlight?

[Nefermandias]

are mountain giants smarter than hill giants?

Yes. But still, they are very closely related.

 

[Voadam]

Yes, in 2nd edition, Hill Giants are 12 HD with Int 5-7, and Mountain Giants are 15 HD with Int 8-10.

Though I have to correct my earlier statement about mountain giants, and they appear to only be introduced in 2nd edition. The 1st edition MM only had the six "default" giants like most other editions.

1e Fiend Folio Mountain giants are on page 42: high intelligence (13-14) 12 HD CN 14' tall

"Like their cousins the hill giants . . ."

1e hill giants are 8 +1-2 HD, CE, 10 1/2' tall and low intelligence (5-7)