[thekingofspain]

Apologies in advance for not adding anything to the discussion, but I believe you mean "I would much rather", because "I'd much rather" != "I had much rather".

[Fezzik]

It can mean I had, I would, or I should, depending on context:

http://www.merriam-webster.com/dictionary/i'd

[taneq]

Wow, that's crazy and ambiguous. I've never heard of "I'd" as a contraction for "I should", how do you tell whether to expand it as that or "I would"?

[ktRolster]

I think it's archaic,

"I should think so"

[startling]

Context.

[JadeNB]

"[H]ad much rather" is a bit archaic, but perfectly cromulent: http://www.google.com/search?q=%22had+much+rather%22 .