There is absolutely no good, proper, or acceptable form of pirating period.
Some people here seem to think that try it before you buy it is acceptable, espescially if you end up purchasing the game afterwards.
The problem with that approach is that developers only see it as a pirated copy of the game, they can in no way know that one of their legitimate copies was sold to somebody who pirated it to try it, liked it, and then bought it.
If every single person did this method the very best case scenario would be (for example) 2 million pirated copies and 2 million legitimate copies sold. So best case is (an apparent) 50% pirate rate to the developer.
Factor in that most pirates download the game and never buy it afterwards, or don't purchase it because they 'didn't like it' then we're talking about massive amounts of piracy. Enough to kill the industry.
The second point is that try before you buy just doesn't make sense. There are review sites, user reviews, information in articles and message boards that should give users pleanty of input to decided whether a purchase should be made. Also, most products consumers buy just don't work like that. If you go into Target and buy an air conditioner you can't ask them to let you use it for a week at your house before you buy it. Why do PC games have to be any different ?
Lastly, and I know I will get flamed for this. Stealing is just wrong, whether it is physical property or intellectual property, it is somebody else's work, and they need to make a living too.
So, to start off with, I absolutely agree that there is never any good reason to steal (pirate). Quite simply, if you can't afford it, or might not like it once you do buy it, you shouldn't have it. Period.
However, quite a lot of the rest of your post is not correct. Yes, there are numerous review sites out there. and yes, there are bunches of individual posts and even Utube videos of most game play. However, quite a lot of the reviews you read are hype, or people on the internet with an agenda and who don't represent the game accurately. So, you can read all of them and still not be guaranteed to have a coherent view or valid opinion on a game.
On the subject of 'Try before you buy', there are a number of precedents for try before you buy. In the Music industry, the industry that is closest to gaming in product and distribution, you can listen to individual tracks and sometimes the entire album on public radio without spending a cent. And this is common practice. With movies (another media entertainment similar to gaming), you can see them in the theater or on TV before you purchase the DVD/Blu-ray. Cars can be test driven. Furniture, you can sit on and try out before you buy. Clothes you can try on in the store. Books you can read in the store or chapters online. All of which are try before you buy. Even food items are sometimes offered as samples at the store.
Also, as far as an artist getting paid for their work. I whole heatedly agree. To a point. Absolutely a fair days wages for a fair day's work. Absolutely! And most developers get that. Most developers are paid an hourly wage for their work. Maybe they get a percentage of the profits, but more often than not, it is a flat fee for their time. So they are getting their fair due (or if not fair, at least what they contracted for).
However, the executives at companies like EA and Ubisoft (and others), want MORE. They want royalties. They want a percentage of every copy on the market. They want more than their fair due. In short, they want a percentage based not on having done the work, but on distributing the product. So the delivery boy wants to get paid more than the painter.
And cry foul when they don't get it. Are they showing a profit, even after paying the 'Artists' for their work? Yes. If they weren't they wouldn't be in that business. Are profits going up? Again, Yes. Likewise, these guys aren't in the business of losing money. In short, pirating doesn't take money out of the pockets of the artists or the people who do the work. it takes money out of the pockets of the execs who want to live fat off of the labor of others.
Also, many production companies will roll out any old crap, finished or not, and try and bilk the public into purchasing it. When sales bomb, instead of owning up to the fact that they tried to push out a game before it was ready, or that it was a crap concept with a coat of paint slapped on it, they cry foul and piracy. Sometimes they even push out crap merely because they don't want to be bothered to create a good game, but only want to grab more money (Diablo 3). Yet they will cry foul on the part of the consumer and say "you shouldn't pirate". They are right. The consumers shouldn't pirate. But then the publishers are just as bad as they are stealing from the public.
In closing, again. Stealing is WRONG in my book. I do not participate in it. I do not condone it in any form. And I do not think that someone can justify it. but this goes both ways. Publishers shouldn't pump out crap and try and steal money from their consumers either. Still stealing shouldn't be done on either side and is unjustifiable either way.