I started playing in 3.5. My first character was a human cleric of Kord with awesome rolls (17 str, 13 dex, 17 con, 12 int, 17 wis 13 cha; one of the 13 was a 7 initially, but DM asked me to reroll it because 'clerics need all stats'). He later on got almost the full benefits of a paladin level (minus HP and BAB) for completing a quest for his god. Played him until level 8 or so (when he was the sole survivor of an almost-TPK and we scrapped the campaign), and all I can remember was that Divine Power+Strength domain+Greatsword kicked ass. I tried to play it like a healbot like the book advised, but I just couldn't keep up with monster damage so most of the time the fighter would drop and I had to do the killing.
Next character was an elven sorcerer that thought Sudden Maximized Fireball was the best thing since sliced bread. Died pretty uneventfully at the hand of a vampire that the DM didn't read the rules for (he thought Gaseous Form made him invulnerable to damage).
And then I discovered the Druid and fell in love with it, while the rest of my group was still messing around with fighters, monks and rangers. For a rather long while I kept outshining everyone(and everytime somebody complained, he got told 'system is balanced, he just plays better' by the rest of the group), and then somebody else discovered the wizard, and we started outshining everybody together.
As a DM, I can only recall one big rookie blunder: party did a service to a balor druid (back then I thought both balors and druids were cool; druids I still do)and they got rewarded with his weapons(sword and whip) and a Staff of the Woodlans, at level 5. Weapons didn't do much (apart from a couple of lucky beheadings here and there), but those 16 charges of SNA VI did.