I forgot to mention that 99% of the time, everything goes down (thankfully). I usually try dishsoap and hot water first. Sometimes successfully, sometimes not. I buy the cheapest paper I can, a lesson learned in a previous home. However, we are not the original owners of this house, and have only been in it for one year. Could a build up of crud be a cause? would snaking help?

Wow... a lot there.

Let's start with the plumbing problem: Toilets can become not effective at flushing if the water level in the tank isn't high enough (there's generally a water level marked inside the tank)or if the water isn't moving from the tank fast enough (water passages clogged) or completely (flapper valve not adjusted right). Check the operation of the toilets by making sure the water level is correct and that the tank is emptying all but the last inch or so of water.

Cleaning the water passages involves either flushing an acidic solution through the water passages or cleaning them with a pipe cleaner, small wire tubing cleaner or similar.

The thing is that the correct amount of water must move from the tank to the bowl quickly in order to effectively flush solids completely through the trap. Otherwise they clog.

If you suspect that the water passages are clogged and you don't want to mess with cleaning them, replace the toilets.

Now for the rest of the story: At 16 and 13 the boys are plenty old enough to plunge their own damn toilet. They are also old enough to do their own laundry and deal with the aftermath of their poor hygiene. Really! You might even teach them some basic plumbing skills by having them fix or replace the toilets. Your future daughters-in-law will thank you.

Since the problem is with all the toilets I would replace one with another brand and see if the problem goes away.

For what it's worth, we have good success with Kohler cimarron, standard bowl only (the elongated bowl leaves bowl residue too often, so avoid that).

For other choices maybe this thread will help:
http://ths.gardenweb.com/forums/load/plumbing/msg1222093711878.html

Get a Toto Drake.

Our old 1.6gpf toilet (came with the house built in 1999) was maddening--used to plug 3-4 times a week! In the two years since we've replaced it, I can count the number of times our Toto has plugged on two hands.

BTW, a nice feature of the Drake (though I don't know if it's considered a true "dual-flush" action) is that it gives you a water-saving "half-flush" if you release the lever right away. If you don't have a lot in the bowl this is usually enough to send it down, as it still gives a powerful initial flush.

FWIW, we also had the Drake installed replacing a fairly new Eljer. It's the best things we've done to our house!

Their food choices, lack of hydration, and general bowel health could also be part of the problem. Try to increase their fiber consumption and keep an eye out for constipation. Tell them any time they produce an obvious "clogger" to leave it to soak and soften. That will give you a chance to check on what kind of cement they are producing. Korean or Japanese style instant mild seafood or kim chi ramen noodle soups are also helpful as snacks but they may not care for the entire flavor packet. Stay away from the soup packages with any red on them unless the kids are really into spices. Stuff like mac and cheese, large amounts of bread, butter, aren't helpful. "Goes together like chocolate candy, peanut butter, and dirty underwear!" is a joke with a lot of truth in it for some.

Wow, and I thought I ventured off-topic...
Way too much information.