It often happens that more than one movie exploiting a certain topic is released in a short space of time. Some examples could be Tombstone and Wyatt Earp or The Illusionist and The Prestige. Last year's No Strings Attached and Friends with Benefits have been one of the recent couples to join this company. Both movies are typical romantic comedies and explore the mixture of sex and friendship in people's relationships. Yet the couple in either of the movies tries not to be involved in a real romantic relationship so both of the films have a lot in common.
No Strings Attached has Natalie Portman, Ashton Kutcher and Kevin Kline on its list while Friends with Benefits does not sport actual Academy Award winners but has a good ensemble comprised of Mila Kunis, Justin Timberlake, Woody Harrelson and a few other Oscar nominated actors. So let's assume there is not a particular winner in this aspect. No Strings Attached starts with a primarily physical relationship before complications arrive while Friends with Benefits begins with friendship shortly followed by sexual exercises but still without any initial intention for romantic development. Again, nothing so outstanding on either side. Both movies show a parent with lots of sexual relationships. And both, Natalie Portman and Mila Kunis, are beautiful actresses although we have seen them looking prettier in other films.
Now, to point out some differences. No Strings Attached is somehow more unfocused. There are events like a funeral and an invitation to an almost unknown person to attend it that seem a bit artificial. The movie starts with a physical relationship while trying to avoid any elements of friendliness. Some of the main supporting characters including Kutcher's female co-worker and his father are annoying at times. The ending is kind of mawkish and on second thought, this is valid not only for the ending.
Although Friends with Benefits seems a bit harried over towards the end, it has less redundant scenes and the whole narrative flows more naturally. The dialogue sports a little more freshness compared to the other movie. The ending is not so sugary despite not being original. The supporting cast (or more correctly the characters they portray) fits better in this movie. Woody Harrelson plays a Justin Timberlake's gay co-worker who is really cool with lots of humorous lines for his short screen presence. Another distinction is Kunis-Timberlake couple is practically in a romantic relationship almost since the very beginning of the film, only they don't realize it at that point.
The above should translate in Friends with Benefits being the better movie but don't expect a huge quality gap here. The film is just a bit fresher than No Strings Attached, funnier and more relaxed. Both are standard romcoms with predictable endings and without unexpected twists during the rest of their time span. If you are a fan of the genre, you can see both. If you are not so much into romantic comedies but you want to pick out one of them, I would suggest Friends with Benefits unless you're a dedicated Natalie Portman or Ashton Kutcher admirer.