Psycho!AJ is extremely similar to Psycho!Mickie James from circa 2005. Both got rejected from their respective loveinterests and acted erratically in retaliation while descending into insanity. Mickie took the the Women's Title from Trish at WrestleMania while AJ strung along Daniel and two of his rivals, then-current WWE Champion CM Punk and future tag team partnerKane for months. The only really differences are how they reacted and the lesbian overtones of Mickie's storyline. One could deign to say that the main reason AJ became so popular is because her psycho character is extremely similar to Mickie's, who became popular for that character.
Alberto Del Rio and John Bradshaw Layfield are both expies of Ted DiBiase, in so far as being richer-than-thou characters who flaunt it in the face of the audience (given that a recession is always either around the corner or already in full swing, this always gets heat).
Davey Richards has also been viewed as an expy of Dynamite Kid.
CM Punk's current heel turn makes him an expy of Harley Race in the way of stating himself as the very best and how people MUST admit that they respect him. This is very similar to Race's heel run as "King" Harley Race where he told his opponents and detractors to bow and kneel before him. Whereas Race had Bobby Heenan, Punk has Paul Heyman. Punk even goes as far as trimming his beard much like how Race's looked and wearing colors matching Race's at the time.
Goldberg seems to have gotten an expy of his own in Ryback, who shares his quiet intensity, short catch phrase, baldness, and goattee. Not that smarks would let anyone forget that.
The Great Kabuki spawned several expies, some of whom spawned expies of their own.
The first was Kendo Nagasaki, who was followed by the Great Muta, Kwang the Ninja (Savio Vega in a mask), "The Japanese Buzzsaw" Yoshihiro Tajiri (who used the mist but not the face paint) and "Tokyo Monster" Kahagas.
TNA's Kiyoshi is an expy of Muta as well. Of course, some might say that TNA is an expy of WCW altogether.
Given who they have working there now (Hulk Hogan, Eric Bischoff, Ric Flair, etc.) that seems about right.
Jack Swagger is basically a whinier, lamer Kurt Angle - both are formers amateur wrestlers that use the Ankle Lock as a finishing move, dress in the traditional singlet and are very very proud of their amateur acomplishments.
Not to mention the usage of American patriotism in their gimmicks.
Mason Ryan will get "Batista!" chants in some of the smarkier cities he wrestles in.
For a period during 2010 and 2011, WWE tried turning Michael Cole into a new version of Vince McMahon's "Mr. McMahon" character. Unfortunately, it failed spectacularly, mostly because McMahon actually was the boss of WW(F/E), while Michael Cole was simply an announcer. Thankfully, WWE ended the experiment at Over The Limit 2011, with Cole returning to his neutral Chew Toy announcer role on Raw the night after — though he does still show a tendency to root for the heels.
Paul Heyman created Mikey Whipwreck as an expy of "The Wrestling School" Dropout Jim Mulkey, a character from the late 1980s-1990s New England promotion ICW/IWCCW.
Mikey gained an expy of his own in Colin Delaney of WWE's mediocre version of ECW.
What do you get when you cross the promotion dominating goals of the nWo with the youth of the Natural Born Thrillers? The Nexus.
Nowadays, it seems every new team that debuts just attacks random people for no real reason like the nWo. Just this past decade, we have had the aforementioned Nexus, the Corre, the Aces and Eights in TNA, The Shield, and now it seems the Wyatt Family will be the same.
YMMV, obviously, but most people seem to see Orton as "Stone Cold without the charisma". While in mid-late 2011, CM Punk seems to be doing a much better job with the "anti-establishment, badass, acts-like-a-heel anti-face" character that Austin played.
The Renegade went beyond being an Expy to an outright Captain Ersatz for UW, as videos were shown of him acting very much like UW, and he had similar facepaint, screamed, no-sold and was billed from Parts Unknown. He defeated Arn Anderson for the WCW World Television Title at the Great American Bash in June 1995 and lost it to Diamond Dallas Page that September. He never got another push, being reduced to Jobber status. The man who Hulk Hogan had said would take "Hulkamania into the 21st Century" never got to see it. WCW released him in late 1998 and he committed suicide on February 23, 1999 at the age of 33.
Flair would later get an expy of his own in "Nature Boy" Buddy Landel
The Road Warriors were a huge smash hit in the 1980s, changing tag team wrestling forever. The various companies couldn't rip off their gimmick (that being "huge face-painted tough guys who smashed-up everyone and didn't care who they beat on") fast enough. The Powers of Pain (The Warlord and The Barbarian) were formed to feud with the Warriors, and the WWF threw a couple of solid midcard performers together creating Demolition. All of these teams ended up feuding with each other at various times.
Road Warriors expies the Blade Runners didn't have much success as a tag team but both members broke out to become major singles superstars: Sting and the Ultimate Warrior.
The Road Warriors themselves made an expy of their own named Power Warrior (Kensuke Sasaki) in Japan, who formed the Hell Raisers with Hawk when Animal was injured and later formed the Hell Warriors with Animal when Hawk passed away.
The Ascension is an expy team of Demolition, the Legion of Doom/Road Warriors, and the Powers of Pain — an asskicking team of large dudes who wear facepaint and come to the ring with intimidating gear. Following their main roster debut they repeatedly almost-lampshaded this — they would mention all of these teams, but only in the context of "well-known and dominant tag teams the Ascension is better than", without directly noting that they share many similarities with those teams.
Meanwhile, Chikara has the Devastation Corporation, who are closely analogous to Demolition - including a johnny-come-lately third member. Unlike the other teams, they've even included the manager, with Sidney Bakabella doing his best imitation of "Precious" Paul Ellering. They also ended up facing Demolition in a match at one point (and lost)
The Rock N Roll Express (Ricky Morton and Robert Gibson) perfected the underdog heartthrob pretty boy babyface team role in the 1980s and spawned several expies, most notably the Rockers (Shawn Michaels and Marty Jannetty) and, later, the Hardy Boyz (Matt and Jeff.)
Zeb Colter and Jack Swagger essentially replayed Sgt Slaughter's early 90's gimmick (used for a few months before he became an "Iraqi sympathizer" during the Gulf War). Slaughter targeted Tito Santana, Zeb and Swagger went after Alberto Del Rio, each basically claiming their opponent were in the United States illegally. And now Swagger even has a foreigner, Antonio Cesaro, as a partner, much as Slaughter eventually teamed with Col. Mustafa (Iron Sheik repackaged as an Iraqi instead of an Iranian).
Colter has a little bit of JBL in him as well, particularly doing the same anti-immigration angle that was done with Eddie Guerrero with Alberto Del Rio. Ironic, considering Uncle Zebekiah was JBL's manager at one point.
And TNA is doing expy versions of much older WWE characters. Orlando Jordan's playing with gay stereotypes bears a few similarities to Goldust. Mr. Anderson is the same type of loudmouth as The Miz (who is an expy of Anderson back when he was Kennedy).
Orlando Jordan is actually bisexual in real life. The gimmick was supposedly his idea, though who can say if he wanted it to be taken as far as or in the direction it was
WWE and TNA have been having a little game of back and forth with the same types of characters. Granted, they're common tropes, but one tends to pop up a few weeks or months after the other, making it look more like a blatant combo of expy and Follow the Leader. Some Examples: