We'll keep this unsolvable. Anyways, I found this game for 4 bucks on Amazon and bought it out of a whim (along with Battlefield: Vietnam), and I want some questions asked.
1) Vista playability.
2) Replay value.
3) Gameplay.
4) Online.
5) Modding.
6) Is the game hack and slash? Don't care if it is, I just want to know how my thief will fare (If possible).
Thanks guys.

1)IDk
2)Vanilla, not alot. Mods vary however.
3)Gah, kinda annoying in my opinion
4)Fun, especially last stand. :) Team based games are awesome
5)A buttload of mods, some a gazillion times better than vanilla.

Works fine under Vista for me, though requires being run with Administrator Privilege Level to start.
Modding side is huge and quite varied. Some high quality stuff is available.

1. Workable
2. Slim
3. OC is crap, expansions are better
4. Excellent
5. Particularly excellent
6. No

2) None for singleplayer campaign.
3) Singleplayer campaign is rubbish, but otherwise it's got solid RPG mechanics.
4) This is the best part of NWN - with multiplayer NWN who needs MMORPGs (and I'm not talking about the grinding)
5) Map making is easy, and scripts are easily found if you Google. My brother started modding NWN when he was only 12. There are a shit ton of mods created by the community too.
6) The singleplayer, yes. The multiplayer is much, much more, depending on what servers you play on.

1) Vista playability. - Yep, even under 64bit
2) Replay value. - Moderate amount if you're the type who likes to try different character types, the story is the same
3) Gameplay. - D&D, click & kill, pwn & n00b...
4) Online. - Some but you have to hunt around a bit, better to organise some coop yourself
5) Modding. - By the bucketload and then some
6) Is the game hack and slash? - Yes for the original campaign, somewhat for the expansions. Some modules are pure talky and others pure combat

To add on, almost every server is different from the others. Most servers prefer to run their own mods, and you don't always have to download additional files, unless the server specifically requests you to do so. Some of the servers are just wild - there are normal hack-n-slash servers, and there are servers with serious hardcore roleplayers. There are servers that do not extend gameplay beyond powerleveling, and there are servers that have castle sieges. So, it all depends on what you need. Ask around on Bioware's NWN forums, GMs lurk there, constantly looking for new meat.

If you bought NWN Gold, you really should buy Hordes of the Underdark as well. Not only is it by far the best of the three Bioware campaigns, many fan campaigns require it.

The expansions are pretty good. But the mods is where the fun is.
http://nwvault.ign.com/

1. Might work, might not. You should have bought NWN Diamond. It'll probably work with compatability modes.
2. The single-player campaign doesn't have much in the way of replayability, except for the Hordes of the Underdark expansion. However, there are a HUGE number of third-party campaign modules for NWN, so you can literally play this game for years.
3. 3rd Edition Dungeons and Dragons + Real time combat. If that sounds good to you, you'll probably like NWN.
4. Online community is pretty big. Not all modules are made to be played in multiplayer, but there's plenty that are, the main campaign being among them.
5. Lots and lots. A set of mod tools comes with the game, and there are many downloadable modules available.
6. Varies from mod to mod. The main campaign is very hack-and-slash, but a thief character should still be able to win if you're clever about it and/or bring a friend to help you flank people. On the plus side, all those locked doors and traps that other people have to put up with are no problem for you, and if you put points into Use Magic Device, you'll be able to use ANY class's tools. Playing a Rogue isn't easy, but it can be fun.

Hmm...okay, thanks a ton guys.