I was introduced to these games via Guitar Hero 2, I remember having such a hard time between medium and hard, then a hard time between hard and expert etc... When Rock Band 1 came out I actually don't know the first time I played it, but I'm sure it was at a party, then I started falling in love with the drums.
When Rock Band 2 came out, that's when I bough my Ions... It's also when I decided it'd be a good idea to do Bladder of Steel on Expert Bass... This is one of the most insane things I've done, I came within a note or two of failing out on Panic Attack (which I think was the second to last song), which would have invalidated my bladder of steel achievement. My guitar was full of sweat, my eyes were dry, it was like 3am.
I've had rock band parties for the last couple of years on my birthday which is around halloween, so I have a ton of memories and pictures to represent those times for sure.
When Rock Band 3 came out I decided to go all out and buy a Roland drum kit, lots of money, but worth every cent. I can't tell you the difference it makes to play on a real kit. I also decided that I was going to hit completionist, and waited paitently for the squier to come out in March. I did eventually hit completionist, but holy crap it wasn't easy (especially since I had almost no legacy DLC).
With the advent of pro guitar, and pro drums all of a sudden DLC felt worth it, so since RB3 came out I've bought a ton of DLC, I also bought Green Day, and Lego RB too - yes, after RB3 came out. Heck I even went to a motley crue/poison concert after downloading some DLC and being reminded of my hair metal days
I am eternally grateful for RB providing exports, at the time it wasn't something the other games were doing, but it was such a good idea, as was charting all the pro drums for songs the whole way through immediately enabling you to re-experience the songs in your library after exporting.
In terms of new music, RB has introduced me to a ton of new music, and even given me a more in depth appreciation for bands I already knew. I remember going through each setlist when they were announced and finding the related music videos to find out which were the hidden gems that I didn't know about. Heck I didn't know Rainbow in the Dark until RB came out, and I spent the whole week ahead of RB 3 release singing that in my car at full volume while simultaneously wondering how the guitar solo would be charted.
Another reason I'm thankful for RB is it actually has helped me get less sensitive about my singing. My voice isn't that great, but spending time singing in rock band has given me more confidence, and I'm pretty sure I wouldn't be singing to my child these days at all if it weren't for RB vox. So I thank harmonix for that.
Rock Band was the title that kept pushing the bounds, multiple players came out with RB1, the midi adapter, keys, pro drums, and the squier in RB3. Amazing.
I know not as many people are playing as were before, but I do hope that HMX doesn't stop pushing the bounds of what is possible in music gaming.