I thought Melee was the slapped together, rushed one between the two.
I know I get on the "Brawl haters" boat far too often, but I just don't understand how anyone could feel this way looking at the two games in any sort of objective manner.
Everything Melee included had purpose in the grand scheme of the game. Every mode, every element was Smash Bros. Most of the additions Brawl had were in breadth, in things that were never Smash Bros. - the trophy shot minigame, the list of Nintendo-published games on every system, the random VC demos... the only thing of significance Brawl added was Stickers, and even those were a fairly simple manner of just pulling a ton of concept art from old Nintendo games.
And in nearly every facet Melee had more effort put into it. Melee's Trophies had a significant amount that were brand new models, whether to represent games that hadn't been in 3D before or simply to look good (did they need to make new 3D models for every Mario character they did?). Brawl had a few new models, but very, very few in comparison. The vast majority of Brawl's Trophies were simply imported from some new game or another - they obviously didn't put in anywhere near Melee's level of effort into that mode.
Most of Brawl's Events felt uninspired and halfassed when compared to Melee. Brawl had nothing that was at the level of Events like Legendary Pokemon, for instance. And I shouldn't have to even say anything about Target Smash, a mode utterly gutted somewhere along the line by the Brawl development process.
Even outside of speaking about stage design or some of Brawl's other unfortunate decisions in regards to modes (All-Star Mode, may you rest in peace), Brawl felt less like a cohesive package and more like a rushed product than Melee ever did.
Which is a big part of why I hope Smash 4 had more Melee and less Brawl.