Two years ago, I joined one of those DVD clubs that lets you buy five or so DVDs for just 49 cents each (plus shipping), as long as you buy another five at full price over the next couple of years. With about a month left before the deadline, I have to buy one last DVD. I want to get out of this as soon as possible, so I can start cancelling all the mail and email that this place sends me.
Usually, after shipping is included, a full price DVD at this place typically goes for around $25, which seems unreasonable— it's easy to get a quality second-hand DVD off of eBay or Half.com for significantly less. The fact that it cost so much was one of the reasons why I put off fulfilling my obligation for so long. I'm probably not the only person who feels this way, since the club just introduced a new section—DVDs for under $15, in essence, an online bargain bin. After rummaging through the "$7.95 or less" section, I've picked out a couple interesting titles, and I invite you, dear reader, to help me make a final selection.
The Contenders
The Four Feathers
Why I like this selection: It looks epic, with all sorts of grand overhead camera angles and men ruminating about honor. It would fit right in my movie collection alongside Gladiator, The Last Samurai, and Braveheart.
Why I don't like this selection: Other than the fact that my DVD collection needs to lighten up a little (I don't have a single comedy), this probably isn't the movie you're thinking of. No Heath Ledger here—in fact, his parents probably weren't even born yet. This is a classic 1939 film, and to be honest, I'm not sure that I 'm enough of a movie buff to appreciate something from another era, especially when there's a more modern remake out there.
What others think: A solid 100% rating on Rotten Tomatoes, and 7.8/10 on IMDB.
Rain Man
Why I like this selection: This is supposed to be a classic, and would be a nice change of pace for my DVD collection.
Why I don't like this selection: I've never seen it. Even if I like it, is it re-watchable? I don't like the idea of committing myself to a movie I may never watch again.
What others think: An impressive 92% rating on Rotten Tomatoes, and 7.9/10 on IMDB.
The Princess Bride
Why I like this selection: I love this movie! It's chock full of clever, quotable lines.
Why I don't like this selection: There are at least two copies of it floating around my immediate circle of friends. Is it really necessary for me to get my own copy?
What others think: 100% rating on Rotten Tomatoes (out of 36 reviews!), and 8.2/10 on IMDB.
Starchaser: The Legend of Orin
Why I like this selection: I have fond memories of watching this in 1989.
Why I don't like this selection: In 1989, I was seven.
What others think: 6.8/10 on IMDB. It could only manage one review on Rotten Tomatoes—and it's a negative review, at that.
For 2 more bucks, I can get…
Galaxy Quest
Which I thought was hilarious when I saw it, but I'm not sure how often I'd want to see it again. Finally having a comedy in my collection is nice, but it doesn't exactly stick out in a flock of sci-fi titles I already own. (7.2/10 on IMDB, 86% on Rotten Tomatoes.)
Gattaca
This comes highly recommended to me, but again, would I want to see it more than once? (7.6/10 on IMDB, 87% on Rotten Tomatoes.)
Or I could spend $5 more and get…
Ocean's Eleven
…which has a 7.5/10 on IMDB, 80% on Rotten Tomatoes.
So what do you think, folks? Who will it be?

I recommend Gattaca! It's a classic sci-fi flick, and I could definitely see watching it more than once.
re: the princess bride and your question, "Is it really necessary for me to get my own copy?"
yes. the fact that you don't own it on dvd already is inconceivable!