Myself? I was a child of the late 80s and the 90s, becoming an adult in 2001. So as a child I remember not always having quarters but pretending to play with the machines anyway, once I grew up and could just go to the arcade and blow $20 on tokens most of the good arcades were gone, pinball was getting scarcer and those that were left were in movie theaters, expensive, poorly maintanced and not that large.
So plan B was consoles. Lots of games got ported to consoles and so eventually I realized I could just buy this stuff. I don't have the room or the money for a home built arcade so a box you can hook up to the TV is pretty good.
About a year ago I got into it hard, I was at EB Games and in the used bin were two Guncon 2's and on the wall was Time Crisis 3. I remembered seeing the game at the arcade and it demanding $1 worth of tokens to play. ...It's been snowballing ever since.

The arcade 'toys' interested me the most, the DX racer sets, the light gun kits and pinball machines. Light guns are the easiest to collect and have a fairly authentic arcade experiance so I've focused there. Six Guncons, three Guncon 2s, one Guncon 3 (I don't even own a PS3!) plus some third party guns for PS1/PS2 and Xbox of varying quality. I've scrounged up ligit copies of every light gun arcade port I could find worth posting.
Point Blank
Point Blank 2
Point Blank 3
Time Crisis
Time Crisis II
Time Crisis 3
Time Crisis: Crisis Zone
Area 51
Maximum Force
Ninja Assault
Vampire Night
Endgame (Okay this one sucks, but it was $7.99 at EB!)
I also pick out whatever arcade ports of racers I can find, Outrun 2/2006, Crazy Taxi, 18 Wheeler, Ikaruga, Soul Calibur, the Capcom and Namco classic collections. Stuff like that.
Also, for those who want to enjoy pinball and don't have the space for a real table, Pinball Hall Of Fame: The Williams Collection features 8-10 authentic Williams tables with remarkably good physics. It's on Wii, PSP and PS2 with rumored ports set in June for PS3 and 360. I have it on my PS2 and PSP and pinball is a great time killing when you're waiting for a bus to show up.

I also don't let my stuff go to waste. It's not some collection that gathers dust in my room unless I'm playing. I run a series of anime and gaming events here in Ottawa, Canada and we pool our resources the best we can to put up an 'arcade' experiance using TVs and consoles. A classroom lined with 10+ systems setup with various games running the full range. It's interesting because the anime fans, they think of Soul Calibur, DDR, RockBand and stuff like that. They rarely think of racers, pinball or light guns, but when we set them up, they're just like "...I can shoot the TV?

"
Sadly true retro stuff doesn't work on them like that. I can put up anything from the 80s and they'll pretty much react like this: "Oh wow! Teenage Mutant Ninja Turtles! I remember this! .........Okay, let's go play DDR'. :/ I think the oldest game I can get them to eagerly play, excluding the Williams pinball tables which date though the 80s to late 70s is Point Blank which is dated 1994. I've been tempted to set up a retro rig next time and offer small prizes for score achivements as an insentive to get them to relive some older arcade history.