I like the Pitchfork feature of the same name, and thought it could be interesting here. You go thru your life and try to discuss the music that was really important, influential or just plain memorable for you at each 5 year interval.
REM - Out of Time
My dad was a big music nut, and he used to listen to lots of college rock/early alternative rock. I know that we took our first family road trip as a full family when I was 5 (my little brother was 2 at time time, and I think we went to Arizona). I remember driving through the desert in the back seat and listening to this album as the desert went by. Whenever I hear Half A World Away I can picture that drive vividly. I don't remember a ton about being 5, but this album can connect me to a part of that.
Beck - Odelay
We lived in Victorville for a long time, and there was an alternative rock station that my dad used to have on constantly. I know they played lots of crap, but they used to have really good stuff mixed in quite frequently. When I was 9, I asked for a clock radio for christmas, and of course I got it. I had my own room, and I used to listen to the radio as I went to sleep every night. At night they had a DJ who would play all sorts of slightly more obscure stuff. I know I heard Portishead, Massive Attack, Mr. Bungle, Helmet, Butthole Surfers, Sonic Youth and a bunch of other bands on there for the first time. I distinctively remember the DJ being very excited about getting the new Beck album. I knew him because of Loser, and the DJ played all of Odelay the night it came out. I wasn't a huge fan on first listen, but I remember my brother and I singing along to Where it's At as we drove down Bear Valley Road heading to get pizza after soccer games, and I know this was around quite a bit.
Weezer - The Blue Album
'01 was a big year for me. I finished my first year of high school, had my first girlfriend, and she broke up with me right in time for summer. My family was going on a trip to the Colorado River for our annual river trip, and I just did not want to be around anyone. I went to K-Mart and bought two CDs to listen to on the drive-Weezer Blue and Weezer Green. I never even put the green album in-the Blue album seemed so comforting to me. It was just geeky, kinda shy guys enjoying having fun with each other. I could get that from the cover. Also, late 2001 Michael Azzerrad put out Our Band Could Be Your Life. I had heard Fugazi because of The Argument, and was really getting into OC Skate Punk stuff, and I decided to pick it up. That book pretty much opened up my world musically.
Joanna Newsom - Ys
I was at UCLA, and it was a big year. I had just switched from Biochemistry to History, I started to really build some great friendships, and I had a car, so I could really go to shows. I discovered lots of great music that year, but nothing remains so vivid as Ys. I remember getting the leak and deciding to listen to it based on a few rave reviews on this board. I put it on as I walked to my European Civilizations class. It was a really nice sunny day out, and the album sounded so perfect that I never made it to class. I wandered around, listening to it on repeat and just enjoying the beautiful day. I've since listened to that album hundreds of times, and Joanna's become probably my favorite songwriter.
Kurt Vile - Smoke Ring For My Halo
I was halfway through law school and working my ass to the bone. I had somehow still found time to keep myself immersed in new music, but went down a more somber and melancholy path, due to my mom's cancer diagnosis and the exhaustion from so much hard work (I was doing death row appeals with the Federal Public Defender, volunteering for the LMU Innocence Project and competing in moot court, and trying to fit a robust social life in as well.) This album was one that I kept turning back to, and still do to this day. Kurt's playing was more developed and nuanced than on previous records, he has great references to songs from throughout his career, and the songwriting had never been stronger. Still a great record, and it soothes me just as much now as it did back then.
Cobalt - Slow Forever
30 found me in a crazy period. I am living back in my home town, teaching high school. My mom passed away when I was 28, after a long battle with cancer, and my life had completely turned upside down. I earned my law degree but had little opportunity to practice in a small, rural California mountain town, so I fell into teaching almost by default, and it's got me convinced this is where the rest of my life is going to lie. This year has so far been defined by a massive album from Cobalt, who are nominally a black metal band but who bring so much more to the field than that. They are heavy and thoughtful at the same time, with huge riffs that stick in your head for days.