When I was younger and saw it for the first time...the only cool thing about it was that it had curse words and I felt bad ass watching it. However, it was on sale for $5 in Wal-Mart, and I couldn't help but buy it...and I basically fell in love with it.
First, you have a guy who is realizing his job is to lie to people, and basically take their money...and he realizes it's wrong...just a good message.
Second, the same guy has never had a true relationship in his life...and he's exposed to the love his client Rod Tidwell shows to his wife and family, and then to this little innocent boy Ray, son of Dorothy (Zellweger). Dorothy happens to be madly in love with him.
Besides having some great lines..."You had me at hello" anyone? The movie is just a feel good show at human nature and this guy finally starting his life over again in his thirties, with a whole new outlook.
Also for years I could always quote that whole "You complete me" part, but I never realized the significance until I rewatched it the other day. In one of the first scenes between Jerry and Dorothy they are in an elevator with a hearing impaired couple, and the guy signs to his girlfriend. When the couple leaves Jerry jokingly goes.."Wonder what he said" (after all the couple was making out so he probably assumed it was something dirty) to which Dorothy replies, "My aunt is hearing impaired...he said 'You complete me'." I never noticed that the line had appeared before.
Finally, what's not to love about a movie that has an amazing Bruce Springsteen song as its theme.