Of the three Onkyo kits the 5305 (active sub) is perhaps the best value.
The 6305 gives you more power and some extra bells and whistles. The Audyssey room EQ potentially makes it a little easier to a better result. The extra coax input is useful.
Other brands
Yamaha used to be kings of the AV package, but they've gone a different direction of late so I'd say they're out of the running.
Denon is having a dabble with their DHT-1311XP AV package. It's competing with the 5305. The speakers in the Denon kit are a bit more substantial.
Pioneer does all-in-one kits based around a integrated DVD or Blu-ray player/receiver rather than an AV receiver. That's of less interest to AV enthusiast.
AFAICT Sony do Receiver & Speaker packages, but the receivers in those packages are more life-style focused. They don't do HD audio decoding, which puts them out of contention. They do have a range of conventional AV receivers with HD decoding, but not packaged with speakers or at prices to compete with the Onkyos.
