What gag you should not pick in toontown

In my experiences on the game, I would go with being dropless or trapless. Though the consequences of choosing the wrong gag would result of not being chosen to go into boss battles with higher laff toons

~The reason to choose toonup is because without it, toons will die because you can't help them gain points on their laff meter. These toons are considered selfish because others toon them, but they fail to toon them back. Sometimes resulting in going sad if you're duoing with someone.
~Trap is useful when luring, but personally, isn't one of the best choices. When you use trap, you can't train by yourself. Yet when you're training with other toons, it can get very annoying. Most toons that I've had experience with are constantly trapping when I lure, which makes the cog unlured again. Traps starts becoming useful at around level six, which you also get ripped off because you only get two TNTs rather than three.
~Lure is very important. Without lure, you can't solo anything. I've played on a 125 laff, lureless toon before and attempted a level four story solo. Without it, the cogs constantly attacked me and I came close to dying.
~Many, many toons hate soundless toons. Sound is the most common gag used in boss battles, and without it, you'll need to be very very experienced with gags. I hear soundless toons are very fun to play on though, so if you plan on making a soundless toon.. I recommend you max out one toon first then create your soundless toon so you know how to work gags.
~Drop is the most powerful gag track, but misses more frequently than others. It's tough training, but after the big weight, it gets much easier and misses less. If you choose it, planting the gag would be nice so your frequency raises. {Which is what most "drop toons" do.}
So in the end, I recommend missing either Drop or Trap, both are less important than the others but are useful at times. :)