TL;DR:
Video.
Settings.
I've been playing with DQ8 (NTSC) for a few days.
I'm running dev-589 from the buildbot. Graphics plugin: GSdx32-SSE4, OpenGL (Hardware).
Enable Widescreen Patches: Checked
Preset: 2 - Safe
MTVU: checked
Aspect Ratio: 16:9
Allow 8-bit Textures: Checked.
Internal Res: 3x Native
Tex Filtering: (Forced)
CRC Hack: Partial
Enable HW Hacks: Checked
Skipdraw: 0
Preload Data Frame: Checked
Round Sprite: Full
Hardware Depth: Checked
Accurate Date: Checked
Blending Unit Accuracy: High
If the screen edge artifacts bother you, go into GS Window settings and adjust zoom to something > 100.30.
8-bit textures is a significant speedup in specific areas of the game (maybe NTSC specific?).
Forced filtering makes the fire and other effects prettier.
Skipdraw at 0 keeps shadows and lensflare/bloom effects looking great.
Preload Data Frame fixes a texture error I experienced in the first dungeon (the Waterfall Cave area) (see attached images). Note: Custom internal resolutions break this fix.
Round Sprite at Full gets rid of the text artifacts while minimizing the screen-edge artifacts.
This has fixed 99% of my issues with visuals so far. And the game looks fantastic. I even turned on Asmodean's shader; the defaults increase the color variations in the trees and skyboxes.
I've noticed two small issues, so far (I'm not very far into the game):
In the in-game menu, when selecting a character, there is a gold-glowing rectangle indicating your current selection. Anything above native res and a bit of this rectangle gets cut out of each side. (see attached image)
Setting tex offset to: 1000 0000 fixes this, but screws up other parts of the menu.
I get HUGE FPS drops when the sun comes into view, while trying to walk around. I think it has to do with calculating the bloom/lens flare effects. I'm not sure what the bottleneck is, though, because GS is very high (75%-90%) but it never hits 100%, and EE/VU stay below 50%. Meanwhile, speed drops to 70%-80% and ONE of my CPU cores shoots up from about 50% to 85%+ (never 100%). Maybe it's memory bandwidth? Lowering the internal res allows me to keep my frames up, but... I prefer to deal with the infrequent slowdown.
Update: Overclocking my VRAM by about 10% gave me +2 FPS, so I'm pretty sure that's my bottleneck (2GB GDDR5 @ 3004MHz).
I was going to update the wiki, but I wasn't sure where to start.
Current specs for posterity:
Intel i7 950, GTX 650 Ti Boost
16GB RAM, 512GB SSD