MaizieD
TBH, I don't see anything wrong with 'go to', there's nothing missing from it as there is in the other examples (go and get, go to see, go to visit etc).
OTOH
"This is the solution we should go to in order to solve the problem" "This is the 'go to' solution"
Neither of these sentences are very pretty, but I can't see that they are incorrect.
I agree about the other examples.
To me the first sentence is wrong because you cannot go to an abstract concept such as a solution, only to a person or place!
And "the go to solution" is even worse, as in this phrase an infinitve "go" followed by the preposition "to" are being used as an adjectival phrase.
What is wrong with saying, as I at least was taught, "the obvious solution" or "the most useful solution"?