Most games qualify very well for rental only. I spent three or four years renting PS2 games, beating them over the weekend, returning them and never touching them again - and I am very glad I did that instead of pay the full purchase price.
I find it hard to lay a finger on the "worth" of a video game. Because if the game is around 8 or so hours long and a great experience, wouldn't you prefer that over a bland, mediocre ~30 hour experience?
I have not played L.A. Noire so I cannot speak to the quality of it, though it seems to be very well done. I understand your concern for hype for this game and games getting more attention than they deserve, but ask yourself this...is it going to hurt you on a personal level that a game reviewed better than you thought it should have? I mean if you didn't like it you didn't like it, what else can you say? You can certainly talk about your personal experience with the game versus the actual quality of the game, but I suppose that's a different conversation.
I like to remember Star Wars by the first 3 films, as the recent 3 were abysmal, although I loved them for what they are when they were released.
The Mass Effect universe seems similar to what our universe would be like given enough time. The thing Brad mentioned on the Bombcast about the new space suits seems awesome (Google "NOVA next generation space suits").
Mass Effect's universe has better races in my opinion, is more in line with reality, and the plot (at least the overall plot, not the one in the 2nd game) is just outstanding in my opinion.
1) There's been a major conflict almost every decade since the 1930s. 2) Earthquakes, grand scale tornadic events, hurricanes, and earthquakes that cause tsunamis are not new at all and go back centuries in record books. 3) Biologists speculate that a species or multiple species of insect goes extinct every day - since there are so many of them that we still don't even know about. 4) Thousands of people die every single day, often of common ailments like diarrhea or measles. This has been going on for decades. 5) Also children in Africa and across Indonesia starve to death every day (and have been for hundreds of years).