Dennis Reynolds (It's Always Sunny in Philadelphia)

The following is a list of recurring characters from the FX television series It's Always Sunny in Philadelphia.

Charlie is a former co-owner at Paddy's and a childhood friend of Mac and Dennis. Frank is his roommate and possible biological father. Charlie is the janitor at the pub, and an illiterate, alcoholic and vapors huffer, who suffers from deep psychological problems, and has anger management issues, and often screams to get his point across. He lives in squalor. Charlie's intentions are often pure, but his plans are almost always foiled. He is also quite good at playing the keyboards and writing songs. He is played by Charlie Day.

Ronald "Mac" McDonald is Charlie Kelly's childhood friend and Dennis's high school friend and later roommate. He is a co-owner of Paddy's and its bouncer. He brags about his incredible hand-to-hand combat skills, strength, and general athletic ability though it is quite obvious he lacks any real skill or even a proper sense of balance. His full name is revealed to be Ronald McDonald in the seventh-season episode "The High School Reunion", though his last name involving "Mac" had been established since the introduction of his father. It is heavily implied throughout the series that Mac is gay, even momentarily coming out of the closet in season 11, and again in season 12, although this time permanently. He also displays anti-semitic views, driven by his Catholic upbringing. He is played by Rob McElhenney.

Dennis is Deandra's twin brother and co-owner of Paddy's. He is narcissistic, selfish, histrionic and vain, perpetuated by his Ivy League education at the University of Pennsylvania. Dennis is repeatedly implied to be a sociopath, and in one episode was diagnosed with borderline personality disorder and prescribed medication. His sense of self-worth is entirely dependent on what others think of his appearance and he often suggests the best way to sleep with a woman is to make her think she may be raped, or by using his personal system, the D.E.N.N.I.S. system (a satire of seduction community techniques for bedding women). Dennis is revealed to be an atheist in the season 7 episode "Sweet Dee Gets Audited." Multiple episodes have shown Dennis to be bisexual, often as a result of his pandering to attention or his need to "get off" no matter the situation. He is also a big fan of the music of Steve Winwood. He is played by Glenn Howerton.

...
Wikipedia