(Something I just wrote on another site, possible using a pseudonym.)
I think people are missing the point that korbanot were not just about killing animals - they were, in the vast majority of cases, about killing your animals. They were a substantial financial "sacrifice", especially in ancient times, when animals were one of the few valuable objects people owned. Instead of mumbling some prayer which you might not even know the meaning of while daydreaming about the Yankees, you were literally forced to put your money where your mouth was.
And in many cases, korbanot were required to include other central components of religious life, such as prayer (chatat, asham, bikurim); charity to the poor (certain shelamim), and so on.
I would hazard to say that sacrifices as depicted in the Torah were more meaningful than any institutional form of worship we have today. Simply saying that "korbanot are bloody and violent, so we don't want them" is superficial and immature, and demonstrates ignorance as to what the Torah actually commands.