I find that the keyboard and mouse is one of the best for controls, with the ability of using hot keys to preform actions quicker. As for ROMs, i've been playing them for almost 5 years so i'm just as good, if not better, at playing SNES games with the keyboard then a controller.
I agree with most of what you're saying, Flathead.

I find the keyboard/mouse combination so much more precise than a controller, not to mention much more flexible (a joystick has a maximum speed (100% tilt in a direction); a mouse (at least, a decent mouse)doesn't

)
I generally prefer PC to console for a few reasons:
1) PC offers higher-resolution graphics, making it easier to see the details of what's happening in the game. For me, a perfect example is the Burnout series on the PS2. This racing game is so fast-paced that you need to quickly identify the difference between a wall, sign, or sharp corner. In the resolution of the PS2, I find this is not always possible. For this reason alone, I would love to see a PC version of the Burnout games. Probably not going to happen though

Quick facts:
Graphic resolution for consoles versus PC:
N64: 320x200 (without expansion pak "high-res" mode)
512x384 (in high-res mode with supported games)
PS2: 640x480
X-box: either 640x480 or 800x600 (not certain)
Gamecube: 640x480, I believe
Wii: 480i (720x480)
X-Box 360: 1080i (1920x1080 @ 25-30Hz)
PS3: 1080p (1920x1080 @50-60Hz) on compatible display/TV.
PC: 640x480 to 1080p(1920x1080 @ 50-60Hz) and beyond.
2) Better performance. Console games, especially in the days of the n64, and even still on the PS3 and X-box 360 (the Wii seems pretty solid for performance), framerates got terrible as soon as the action got hot. To me, this seems like a pretty lousy time to get poor performance from the game. PCs allow for adjusting graphic options to fit the computer, allowing the player to get maximum performance from their computer. Console players need to use the "Factory" graphic settings, which aren't always ideal for the console the game is being played on. I know I've done my fair share of complaining about a game's performance on console, whereas on a PC I'll just change graphic settings until I get the balance of quality and performance that I like. In single player, performance probably usually isn't *too* bad. Multiplayer is where this really tends to suffer. Anyone who has played Perfect Dark in cooperative mode on the N64 knows what I mean

The PS3 also seems to suffer framerate issues in high-detail situations (less than the N64 but much more noticeable than on my PC).
3) The PC is able to support LAN play for many games, allowing greater flexibility for multiplayer gaming. Many console games have fantastic multiplayer modes (Mario Party, Smash Bros, etc.) which work amazing as console games, and I don't care to see these sorts of games on the PC. The games I feel suffer the greatest when playing on consoles are adventure games (the Gauntlet series; players can't travel much distance away from each other as they must all be visible on one screen), racing games (cutting the screen size and framerate for multiplayer can be painful at times) and shooter games (see racing games, but factor in the "trying to aim a gun with a joystick" factor

I can't shoot with a controller; I need a mouse LOL)
Console games: 4 players maximum
LAN gaming: Depending on the game, up to 64 players +
4) The PC generally allows more customiziability than similar console games. With PC games, the online community may develop modifications for the game, expansion packs may be released, patches may solve problems that exist upon the game's release. With consoles moving towards the online world this difference is being cut down, however many consoles require paid subscriptions on top of my existing Internet fees. This just isn't ideal for me. I would rather have access to game updates, mods and communities via my existing internet connection.
Bottom line:
If a game is released on consoles and PC, I will pick the PC version 99% of the time. I must say though, I love being able to pull out a console with friends, provided it isn't a shooter game because I can't aim with a controller
