I blasted through 2002 and have thoughts:
Top matches, not necessarily in order and probably missing a few. There are a LOT of very good TV matches, but I'm just pointing out the matches I think you really should go out of your way to see if you haven't watched this era.
Ric Flair vs Vince McMahon Street Fight Royal Rumble
Rock vs Hulk Hogan WM 18
Undertaker vs Ric Flair WM 18
Kurt Angle vs Undertaker vs Rock Vengeance
Rock vs Brock Lesnar Summerslam
HBK vs HHH Summerslam
Edge/Rey Mysterio vs Kurt Angle/Chris Benoit No Mercy
Brock Lesnar vs Undertaker Unforgiven
HHH vs RVD Unforgiven
Brock Lesnar vs Undertaker HIAC No Mercy
Chris Benoit vs Eddie Guerrero Armageddon
Booker T/Goldust vs Dudley Boys vs Christian/Chris Jericho vs William Regal/Lance Storm Armageddon
Kurt Angle vs Rey Mysterio Smackdown 9/12/02 (imo better than the Summerslam match)
Kurt Angle/Chris Benoit vs Guerreros Smackdown 10/17/02
Kurt Angle/Chris Benoit vs Guerreros Smackdown 11/28/02
Eddie Guerrero vs Rey Mysterio Smackdown 11/14/02 (imo their best singles match against each other in WWE)
Chris Benoit/Kidman vs Guerreros Smackdown 12/12/02
Edge/Kidman vs Guerreros Smackdown 12/26/02
Goldust/Booker T vs Chris Jerichio/Christian Raw 12/23/02
These are the ones that really stood out to me as being very high quality, although I am sure I missed/skipped/didn't pay attention to some others. The reality is Smackdown every week from the split on has multiple good TV matches. Pretty much any of the Smackdown six related matches are good, almost all of the cruiserweight matches are fun TV matches, Kidman getting mixed into the SD 6 is always good, literally every match Brock has on SD after winning the title is worth a watch (I think the stand out probably being against Chuck Palumbo), Taker has a similar run of fun TV matches across both brands when he was Universal Champion, HHH has some really solid old school style matches against mid carders on Raw after getting the WHC, and almost all of the Booker/Goldust tags all year long are good. There's the Edge/Angle and Edge/Eddie series that are fondly remembered but Edge doesn't do it for me so I don't really care about them. TLC on Raw, Taker vs Hardy ladder match, etc. All of Rock's TV matches are good (I'd say the ones with Eddie and Angle probably stand out). There's a really solid Austin/Flair match from Raw.
Now, on to booking stuff. It really does feel like a different company at the start of the year to the finish. Pre split was still VERY Attitude Era crash TV, short matches with tons of interference, etc. The presentation changes on both shows after the split, matches become longer (although not nearly as long as modern era) with cleaner finishes more often, there's generally less backstage shenanigans in the sense of big scenes and angle taking place backstage like you got during the Attitude Era. Vince pretty much being absent from TV after June helps with this, although Bischoff and Steph were ALL over the shows and each others shows most of the time anyway, it felt different than it being Vince every week causing trouble. The Undisputed Championship was booked so well, it sucks that it only lasted a few months. Compare that to how the WWE/WHC titles were booked and how Jericho was booked as double champ and it's wild. Both shows were just trying shyt out which led to a LOT of angles, push, and teams being abruptly dropped. Like John Cena getting the big push for 2 against top guys then they just....stopped having him on SD and then had him on Velocity feuding with cruiserweights and Rikishi. Same with Orton, who they gave 4-5 weeks of a good push on TV as a young rising star then just....stopped doing anything with him. You have things like 3MW being the super heavy team to losing handicap matches within 2 months. Teams like HurriKane coming out of nowhere and being dropped just as fast with no angle for either, then Hurricane briefly forming a team with Goldust only for that to get dropped and Goldust go back to teaming with Booker and Hurricane more or less vanishing from Raw the rest of the year.
One thing that really sticks out to me is how many gradual heel/face turns there were throughout the year. There aren't many big shocking turns. Most take place over weeks if not months. Examples: Ric Flair from face owner to heel owner (although his return to face and his return to heel later in the year were both very rushed), Taker's turn from sadistic dikkhead bully heel to patriot to respected vet dapping up the new gen, Booker T going from loser heel to comedy heel to comedy face to pure babyface, Brock's turn from straight muscled up monster to doing some heinous mind games with Taker to getting some respect beaten into him and being humbled into a face to the point Heyman turned on him for it, Benoit's face turn purely from match quality.
I would say Taker is the MVP of the year, by far the best work of his career, and he played so many roles throughout the year from sadistic bully to whiny chicken shyt to big dog of the yard to the respected vet taking younger talent under his wing and all of it was played to perfection. He's really a fulcrum for so many angles and stories throughout the year. His fukking with Flair in part leads to the brand extension. He stirs the shyt in the Undisputed Championship realm the entire time it exists, and he really cements Brock as truly THE MAN after he beats some respect into Brock and pushes him into deep waters Brock had never been to, and Brock came out of it a changed man and wrestler. Kurt Angle is a runner up MVP, maybe more so in some ways but he was used more as an over all utility guy for most of the years and not in as important of a role as Taker was. Physically, I don't think there's ever been a more stud athlete alpha male in any company in any era than Kurt Angle in 2002. He's having good matches against literally everyone, he does comedy angles and promos as good as anyone, he does serious angles and promos as good as anyone, and he can switch back and forth without losing any credibility. However, most of the year he's used just to have good matches, put people over, or be used as filler and foil for other storylines.