Depends upon your current level.
If you are a Q 25~30 tester, then master the Kaplan
Math Workout book.
If you are in the Q30~35 range, then go for McGraw Hill (12 tests) and Kaplan 800
Assuming that you want to break into the low-mid Q40s (my current short term goal), then yes, the OG + supplementary guide + retired tests + GMATPrep (with reloads) should help.
Now, if you are already a Q45 batter aspiring for a 48+, the only recommendations I can offer are GMATClub challenges
and ascenteducation.com. Somebody once said that the 4GMAT workbooks were very challenging too. 48+ is really "no man's land" for us non-engineering/humanities majors.
Finally, if and when you are ready to cross the Q50 to 51 mark (96 to 99%ile), do a search on all the kevincan posts in the math forum