1.- First thing,
do not ever buy another HDMI cable for more than ten bucks (even that is too much). HDMI cables in stores are a scam for the retail stores to pad their profits since prices on HDTV's have fallen so low profit margins are minimal. I've gotten six HDMI cables from
http://www.monoprice.com for less than $50 bucks (total with shipping & taxes included) for me and friends/relatives/co-workers, all of whom report no problems whatsover. Yes, the brand HDMI cables sold on stores are a little better than the $5 HDMI cables sold online but they're not $85 better! HDMI is a digital conduit, it's either on or off (no in-between half-ass signals like analog). If there's a way you can beg your way into returning the $90 HDMI cable back to Best Buy I'd do it (assuming they'll take it since you already opened the package).
2.- I'm not sure if your model of HDTV does, but a good deal of HDTV's on the market have input-independent settings so what you do tweaking on whatever you have connected to S-Video 1 (for example) is different than the settings you'd have for what is hooked on HDMI 1. Read your Aquos' manual carefully to see if it mentions this. Calibrating the TV would mean messing with its inner circuitry and service menu (i.e. the menu that only technicians can access inside the TV's circuit board) but simply messing around with the settings is easy. Just remember that what looks good for a golf game in the afternoon will not be the ideal setting to watch "Alien" in the dark late at night. Don't kill yourself trying to find the ideal sweet spot that will make everything you watch on your Sharp look great because it doesn't exist. Hopefully, if your model has input-independent settings, you can tweak one input for games, another for DVD viewing, another for analog cable viewing (and yes, you should upgrade to an HD cable box ASAP), etc. Enjoy the TV but don't expect it to look perfect all the time.
3.- I've been to AVS Forum and other sites and you're right, not a lot of info on this Sharp model from actual owners. From what I've read this is a gaming-friendly HDTV model (hence the many composite inputs for the many pre-XBox 360 systems like PS2 and Genesis that were composite or S-Video only) so make sure to engage/activate 'Game Mode' to minimize lagging between controller input and on-screen movement. 'Game Mode' de-activates the TV processing so lag is minimized, but that processing is needed back when you're watching non-gaming material. Most HDTV's default out of their 'Game Mode' and into regular processing when switched to another non-gaming device, but make sure you read about this in your Sharp's manual so you know what to do. Just remember this simple rule: if you're gaming 'Game Mode' on, if you're not gaming 'Game Mode' off.
4.- The higher up the video connection chain you go the better the picture will look (for anything: DVD players, gaming, Blu-ray) so try the Y-R-B (i.e. component) and HDMI connections as often as possible, and only connect S-Video or composite when that's the only output out of the player. I have composite and S-Video cables for my older game consoles but went out of my way to find higher-than-SVideo cables for my pre-360 systems (VGA for Dreamcast, component for Gamecube/XBox/PS2/PS1, etc.) just to get that extra bit of sharpness and detail. This explains your cable box (analog non-HD) looking crappier than DVD. DVD is directly connected to the TV with HDMI (optimum connection) while the TV signals from the cable box have been compressed and gone through tubes, wires and now an inferior composite cable before getting to the TV. Remeber:
your TV converts ALL the signals it gets into 1080p because that's the resolution of the panel. The better the cable connection (with component and HDMI being the best, followed by S-Video, composite and RF last) the better helped your Sharp is in converting old 480i analog signals into 1080p digital one's.
5.- Do you live near a city or TV station with an HDTV station? If you do connecting a rabbit antenna to your HDTV's back ($20 at most electronic stores, less in some) it might be worth it to see if you can get OTA HD TV stations. This is the 2nd purest and best (not to mention free) way to get the higuest-quality HD experience after Blu-ray. If you happen to get an ABC affiliate with the antenna make sure to watch the next "Lost" in HD: simply stunning (best high-def anywhere).
6.- At 32" you're barely getting the benefit of the 1080p resolution. If you're happy with your DVD viewing then maybe Blu-ray isn't worth the expense at 32" (most experts think you need at least a 46" or higher sized HDTV to truly appreciate high-def media). Before you buy, try. Ask a friend or neighbor with Blu-ray (somebody you know must own a PS3) to come over, hook up the machine with HDMI to the Sharp and watch some Blu-ray movies.
7.- At AVS Forum (the Mecca for AV enthusiasts) a lot of people report success using the THX calibration tests that come with all the "Star Wars" DVD's (and some Anchor Bay movies like "Evil Dead 1 & 2"). The 'Video Essentials' mentioned above is great but why not try the "Star Wars" DVD's (particularly "Attack of the Clones" and "Revenge of the Sith") as guinea pigs? They're as good as DVD's can possibly look on an HDTV without being HD-DVD's or Blu-ray's.