Budokai 3 holds up extremely well and should be played by fans
I was around 13 to about 16 during the era when these games were coming out. At that age I was in the prime of my Dragon Ball Z fandom. I played all 3 of the Budokai games to death during that time and I have a great deal of nostalgia for them, so I absolutely had to buy this collection. This review will sort of be my experience in replaying these games after having not touched them in 5 or more years.
The Dragon Ball Z Budokai HD collection collects Dragon Ball Z: Budokai and Dragon Ball Z: Budokai 3. As you can see there's the glaring omission of Budokai 2. I think its absence actually makes a lot of sense. This collection doesn't really feel like any other HD collection since those this game is targeted to are really only buying it to play Budokai 3 again and Budokai 2 in a lot of ways feels like a beta version of Budokai 3. Since Namco Bandai can't really charge $40 for a single HD up res it feels like they threw Budokai 1 in here as filler. And that's really all it's good for, that and some easy achievements/trophies.
Budokai 1 does not hold up. When it first came out back in 2002 it was the peak of Dragon Ball Z fighting games and was the first game to accurately capture the story, spirit, and chaos of the fighting of the show to something playable, fun, and satisfying. Dragon Ball Z fans really had nothing else to play at the time (Legacy of Goku had come out earlier that year but it was terrible) so it served its purpose and was good enough until Budokai 2 came out a couple of years later.
Budokai 1's inclusion in this collection serves mostly as filler and partly as a contrast to the incredibly good Budokai 3. Playing through Budokai first and mining it for its easy achievements/trophies (which takes about 2 hours if you skip the cutscenes) will only make you appreciate how much better Budokai 3 is. Budokai is very unbalanced, which is saying something since this series isn't really about balance but more about portraying what would happen in the show. Pretty much any main character or Super Saiyan can beat any other lesser character easily. This was continued on in the rest of the Budokai games. Some characters are just stronger than others and there's really nothing you can do about it. But the real issues come in when you realize that tall characters can't hit short characters. In later games characters would bend down and punch them, here they just swing at the air over their heads.
There are other weird inconsistencies like Kamehameha attacks being orange unless you're playing as Cell, again, almost all of these problems were fixed and made right in later installments. The game is also very plain looking. Later games, like Budokai 3, used gorgeous cel-shading to make some incredible looking games.
What you're coming to this collection for is Budokai 3. It's the pinnacle of the Dragon Ball Z game franchise and no other anime licensed game has surpassed it in my opinion (you can take that Tenkaichi and place it firmly up your ass). Budokai 3 is incredible. The fantastic graphics, insane amount of unlockables, weird and obscure fan service nods, and the all around chaotic nature of the fights makes it an experience that perfectly encapsulates the show's over the top nature. Punches look like they hurt, beam attacks look like they should and do the amount of damage you would expect. Pulling off super moves is a joy to behold and their over the top nature (sometimes even destroying the stage you're playing in) is frequently hilariously awesome.
One of the best things about Budokai 3 is its single player mode called Dragon Universe. In it you play as most of the main cast and, yet again, play through the story of the show while you fly around an over world map leveling up, finding collectibles, or inadvertently triggering secret dialogs that lead to unlocking characters. The fact that you have to play through some of the main characters stories twice just to get their full story or having to beat a certain opponent with a certain move to unlock characters or abilities gives Dragon Universe an insane amount of replayability.
But the game doesn't end there. After beating Dragon Universe with all the characters you unlock Dragon Arena where you take any unlocked character and fight in fight after fight earning experience points until you lose. This mode made more sense back when the game originally came out. There wasn't any online multiplayer then (or even now) and the point was to level up your characters and then swap your codes with friends so they could fight against your character. Now it sort of feels like a useless feature but the Dragon Arena is a nice way to continue after you've finished Dragon Universe and want to keep playing. There's also a great World Tournament mode that you can play with up to 8 friends by passing around the controllers.
The attention to detail in Budokai 3 is nothing short of amazing. It's clear that the developers had a love for the series themselves and those who know the show inside and out will no doubt appreciate all the subtle nods to the cannon and moments that happened in the show. Little things like Piccolo not being able to power down after using Sync with Nail or Fuse with Kami because they were permanent to his character in the anime really shows that the developers knew their stuff. Some may say they were a little too slavish to the source material but I personally love it.
Let's talk about the HD upgrade. Mostly nothing of note has been done to either game in the transfer. There is some heavy anti-aliasing so everything looks smooth with Budokai 3 benefiting from this the most. Budokai 3 looked great then and it looks even better now. I swear, it could pass for a current generation game. Dragon Universe and the fights are widescreen but in both games title screens, menus, and cutscenes are all 4:3. It's a shame that the entirety of the games could not have been in widescreen but it's understandable. They at least put nice looking borders in the 4:3 sections so it doesn't look too outdated. There's also no online multiplayer at all so the versus mode is limited strictly to local only. Which is a shame because dueling is some of the most fun you can have in the game.
So this collection isn't really a collection at all. If you're buying it then you're buying it to play Budokai 3 again in high definition. If you're not a Dragon Ball Z fan there's nothing I can say to you that will make you even remotely interested in playing these. But that's ok, these games aren't for you. They're not even for fighting game fans since they're not that kind of fighting game. All of the characters essentially fight the same with their differences being in their power levels and special moves. This game is for Dragon Ball Z fans and if you are one and have never played Budokai 3 then this is the perfect time to play the very best that Dragon Ball Z had to offer in video game form.