I just finished GTA3 with 100% completion. I know, it came out nine years ago. Still, it feels good to have it really mastered. What a help it was to do the ambulance up to level 12 so I had infinite run. Plus, it was helpful to do the import/export garage missions on Portland and Shoreside Vale so I had access to any car I needed. I even took the advice of a long ago walkthrough and went to my hideout after escaping Catalina's mansion on the last level. Having access to the rocket launcher and plenty of shells helped the mission immensely. 
 
It's a great game. I think I could play it over again trying for 100%. But it's time to move on to Vice City and San Andreas.