Agreed. The whole phrase "You can't polish a turd" is true. Yes, you can use effects, plugs to help a sound, but your source is KEY. Your source is vital.
I have a feeling this is going to be one of those questions where the answer becomes "Whatever sounds best to you". And in all honesty, it is true. A common misconception is that there are certain, plugs, effects that will make your sound more "studio like" but honestly, there are SO many factors that contribute. If you narrow it down however, to "what are your go to plugs for this" or something like that, you may get some "suggestions" but again, it will never be definative.