I pretty much lived for the updates during that time. My favorites were definately the character updates, even if they were returning characters; I absolutely loved seeing the updated character designs and gushing over the details (ZOMG, look at how good *insert character here* looks!) After that is was the stage updates.
Favorites:
1. King Dedede (the only one of my top 5 most wanted characters that made it in playable form. The others were Geno, Megaman, Ridley, and Takamaru.)
2. Announcement of the SSE and cutscenes (I was disappointed by the finall product but not horribly like most people were.)
3. Online play (for the first time in years, I actually had a dependible sorce of competition. Now, I even host online tournaments.)
Least favorites:
1. Pretty much most of the updates in November/December. (Most were painfully dull or obnoxiously obvious. It made the wait for the game even more painful.)
2. Special moves for returning characters. (Only Mario and Bowser recieved new specials moves so it sucked getting info on movesets we had already know about for six years.)
3. A close tie between Sonic and ROB (Sonic: extremelly obvious but people acted like it was an enormous suprize despite being the most likely third party character for a buttload of reasons that were apparent as early as the annoncement of the game. ROB: confirmed the 39 character roster and that most of the cool characters people wanted weren't going to make it. To me ROB opitimizes Brawl's overall lackluster roster and how a lot of people's expectations were completely crushed. It's fine because Melee's was even more so and it gives me a reason to actually look forward to a sequel in the future.)