It's difficult to make generalizations about the specific brands of underwear that gay men in Europe and the United States prefer, as people's preferences for underwear can vary greatly regardless of their sexual orientation. That being said, there are some brands that are popular among the LGBTQ+ community for their quality, style, and inclusive messaging.

In Europe, some popular brands among the LGBTQ+ community include Diesel, Bjorn Borg, Andrew Christian, and ES Collection. These brands offer a variety of styles and designs, from traditional boxers and briefs to more revealing and provocative styles.

In the United States, some popular brands among the LGBTQ+ community include Calvin Klein, 2(X)IST, Andrew Christian, and TomboyX. These brands are known for their quality and comfort, as well as their inclusive messaging and efforts to promote body positivity and diversity.

Again, it's important to remember that everyone's preferences for underwear are unique, and what works for one person may not work for another. Ultimately, the best way to find the right brand and style of underwear is to try out different options and see what feels most comfortable and appealing to you.