If you want to get the most interesting ACARS stuff listen while there is bad weather near the major airport you live closest too. 99% of the ACARS messages i send/receve are for ATIS and PDC's (not that exciting) but when the weather goes bad in EWR or ORD, you will start to pick up ALOT of ACARS messages between crews and dispatchers discussing the impending fuel situation, possible divert options, re-dispaching of flight plans to lower reserve fuel, ect... often resulting in a pissing contest of sorts between us and the dispatcher.(those can get downright amusing)
Although the most significant message i have ever received inflight via ACARS was when we were notified that the Bears lost the super bowl.
Tom