I’m sorry if this question has been asked elsewhere, I did have a brief look and couldn’t see anything. Having Greek I know that I go to LSJ’s lexicon and Smyth’s grammar. The same for Gesenius and BDB in Hebrew.
What would be the ‘classic’ combination for Latin? Is there even one or is that a silly question?
Allen & Greenough or Gildersleeve & Lodge. You can find new paperbacks on Amazon, or used hard-bound copies on Abebooks, and A&G is also available on-line, though I find the on-line versions very difficult to use.
The Allen & Greenough is a great reference grammar. All the rules with their respective exceptions are present there. It`s full of examples, and very welll organized. It has a good index also. But no less useful is the Charles Bennet (downloadable here: http://www.textkit.com/learn/ID/53/author_id/12/). It is smaller - it has not as many sub-items -, but more to the point.
As to a lexicon, Lewis and Short is very good indeed.