There is no way for any of us to give you cut and dried suggestions without more information but I can give you a few general suggestions...assuming of course that you have an "average" game....speed, revs, rotation and tilt.
For THS the Jet Black Taboo is a must have. It is perhaps one of the best all around THS balls I have ever used. If you are looking for a lighter condition ball in addition to then Jet Black, I suggest the Grape Vibe. If you want one for heavier than the Jet Black can handle, I suggest either the Purple Pearl Taboo or the Brick with a strong layout.
If you don't get along well with asymmetrical balls then look into the Arsons...the Low Flare for those with above average revs or below average speed, the Pearl for lighter, broken down shots and the Hybrid and original for medium and slightly heavier.
There is so much versatility in the Hammer line that you have lots of options which will also allow you to go from ball to ball much easier.
Again these are just generalities assuming you have a typical, average Joe type game.