The question of this tipic is - are you into quality sound? A good home-cinema maybe? And by quality i mean Hi-Fi and Hi-End. And it's not about Hi-Fi sticker you see on cheap electronics these days. I'm hoping to find audiophiles among Seikai fans and hear about their stereo systems. If you got one- let me know about it, as well as of your impressions and music preferences!
Anyway, as for my own Hi-FI - I own slightly old but kicking Denon 2105 AV receiver:
...which was surprisingly good for middle-range receiver back in 2006 among all the rest (under 1000$) "bringing hi-end sound to masses" as they said about this one.
... and fresh set of Mordaunt-Short Mezzo acoustics (speakers) that i bought a couple months back
These have truly changed my views of Hi-FI for while they are priced as some cheaper solutions (about 550$ for the fron pair) they blew many middle-end Hi-FI speakers (typical floor-standers that are around 1000$) out of the water. If you're into quality sound that is as close to original as possible, especialy when it comes to live instuments and you listen to wide range of music styles from classical opera to metal but you only have 500$ - these are for you. The only other speakers that are close would be B&W 685s for they are slightly more..."muscular" i'd say but at expense of speed and detail...B&W would be good for those who don't listen to classics much or stuff like Blackmoore's night in favor of rock/alt rock etc. And i don't believe all kinds of electronic and "bum-bum" stuff needs quality sound due to it's simplicity.
As for accessories - i use MonseterCable "Reference" (bought it cheap, under 30$/meter) and something i am proud of - a custom made supports made from 10mm armor plate filled with mix of sand and 12g drumming, each weighting around 40kg, of course it's mounted on steel studs (if it's the right word) on top of granite plate (stole idea from "Stereo" magazine).
I'll try to add more information on sound of these and some photos of my own later. But i hope to hear about your sound solution no matter if it's a lot more expensive or cheaper one. I'll also try to add new stuff here every time i hear new speakers, headphones, receivers and stuff since i visit hi-fi shops often.