Consensus of best version of legends?

For the guys you have listed
Hulk Hogan - I can’t choose between the RSC exclusive in Blue or the DM Hogan in yellow.

Roddy Piper - the Wrestlemania 2 boxing version w/Mr T has the best Piper facial likeness

Andre the Giant my fav is either the 2 in 1 machine Andre (with yellow hogan boots, to make WM2) or the legends Andre in the black singlet.

Macho Man - the new Ultimate Edition Macho is the best IMO, but there’s so many good savages out there.

Ultimate Warrior - So many great warriors... Hall of Champions Warrior

Ted Dibiase - either the entrance greats or the new legends
Animal - red shoulder pads LOD version
Hawk - Red shoulder pads LOD version

Sgt. Slaughter - the HOF figure

Undertaker - either the new legends or the old Wrestlemania elite with the basic head swap and gray tie.

Hulk Hogan - DM or upcoming UE for pre NWO Hollywood Hogan.

Roddy Piper - Mine was the EG head on Funk’s torso with the HOF Piper lower body. But I will be switching the head the the WM2 set once my extra set arrives. But for a stock figure I would say EG.

Andre the Giant - 4 pack or 4 pack with WM cart figure head.

Macho Man - DM WMIII. I like that it doesn’t used the ripped legs that the L5 & All-Stars figures use.

Ultimate Warrior - WalMart Flashback figure.

Ted Dibiase - ring gear HOF(?) suit L9.

Animal - Legends Series 1.

Hawk - Legends Series 1 or L1 with E20(?) Cody arms (DM Steamboat’s arm mold)

Sgt. Slaughter - HOF series 1.

Undertaker - DOD Series 1.

The Matty Collector legends (DDP, Tully Blanchard, Arn Anderson, etc) are great figures but expensive now especially Moc

Hulk Hogan - DM
Roddy Piper - HOF
Andre the Giant - Matty Legends
Macho Man - L5
Ultimate Warrior - E44B
Ted Dibiase - Chase L9
Animal - L1
Hawk - L1
Sgt. Slaughter - HOF
Undertaker - E44B

Isn’t the Defining Moments Undertaker his ministry era?

A lot of these are going to depend on the era you want/collect:

Hulk Hogan: For a classic 80s look, the DM is almost perfect, but the upcoming Survivor Series fig looks like a home run. However for NWO, the Ultimate might be his best.

Roddy Piper: I'm a fan of the Hall of Fame Elite, but the head with the Mr T pack is perfection, swap it out and you have a flawless mid 80s heel Piper.

Andre the Giant: Closest I can think is the E29/Legends Andre but my personal version is the Heenan Family Andre with a head swap with the WM ring cart basic and E60 arms.

Macho Man: For an 80s Mach, the upcoming Legends release is nigh perfect, but throw in the DM robe and you're set. Neon cowboy look tho, the WM VII DM holds up but I'm in love with the Ultimate

Ultimate Warrior: This really depends on the era. The Ultimate was good and I feel like the Amazon Exclusive UE might be the best bet. As far as Elites, the RSC and original Legends figure are musts.

Ted Dibiase: I have the Hall of Fame Elite with the EG suit.

Animal: Depends if you want the NWA or WWF version. You could swing either way but I loved the Road Warriors' run in NWA.

Hawk: Same with Animal, which version of the Road Warriors do you prefer.

Sgt. Slaughter: Hall of Fame is my default Sarge.

Undertaker: This is the hardest, DoD is your best debut Taker, Legends for New Gen, Network Spotlight with a headswap for a makeshift Attitude Era Taker, E18 for ABA, etc.

It might be worth it for you to get the Horsemen 4pack and Heenan 4 pack. You can probably find both for a decent price and not have to replace most of the figures besides Flair and as of now it's the only way you can get Barry Windham and Big John Studd. His upcoming Legends figure looks to be better with a robe.

Was wondering if any had opinions on others like Flair, Mr. Perfect, Sting, Luger, and all the other legends that have had a few versions of?

Yep (for better or worse). It won a fan poll online over two other choices last year, I believe it was.