bikingjahuty, what's the one PS2 game you're still looking for?
Any cartridge-based console - If I come across something that looks interesting & is really cheap, I'll pick it up, but I never go out of my way to collect for these. I lived them, they were great in their time, but I just do not enjoy going back to these systems very much.
PS1 - Any RPGs, and any other title that looks interesting & is priced reasonably. Most of the early polygon games don't hold up very well (this goes for N64/Saturn as well) so there aren't many action/adventure games I pickup for the system.
Dreamcast - I'm pretty much done with my DC collection at this point. I have almost all of the games that interested me, and the ones I don't (Project Justice, Canon Spike) are ridiculously priced.
PS2 - Probably still my favorite system, just barely edging out the PS3. I collect any & all RPGs I come across for it as well as pretty much anything else that I remember enjoying, looks interesting, etc. Love this console.
Gamecube - I really like the system, but I don't heavily collect for it. I have most of what interests me - still a few I'm looking for, but haven't been making them a priority.
Xbox - If I come across an exclusive that interests me & is really cheap, I'll get it.
PS3 - I've been heavily collecting for the PS3 over the past year & a half or so. Games are dropping down really cheap these days, so I'm getting anything that interests me while I still can - don't want a repeat of the PS1/PS2. Almost have a complete set of the RPGs for it (excluding any that had improved releases on other systems). All multiplats of that gen I get on the PS3 as well.
360 - Exclusives only, and mainly the JRPGs & SHMUPs that were released exclusively on it. One of my least-favorite systems overall.
Wii - I *love* collecting quirky titles for this system! I cursed myself when, about a year and a half ago, I was joking with a friend about reading where someone said there were easily 50 games worth owning for the system. Then I started really looking at what was out for it & currently have over 100 titles - with more on my wish list.
Surprisingly awesome little system once you get past the shovelware.
PS4 - My current primary system, all multi-plats are bought for it & I'll end up getting all the RPGs for it eventually.
Wii U - Trying to stay up on the games I want for this one so I don't have to track any down - tho I'm already missing Pikmin 3 & the Wario game that are uncommon in my area. There are some really great games for this system.
DS - I've really slowed down collecting for this, at this point if I come across something interesting & cheap I'll grab it but I'm not going out of my way looking for games for it anymore. That said, I picked up a TON last year, so I feel like I have a pretty diverse collection.
PSP - Mainly focussing on the RPGs, and there are a ton of them. Unfortunately I almost waited too long to really start collecting for this one, and games for it are becoming scarce in my area.
3DS - I have most of what I want, minus a few glaring omissions like A Link Between Worlds. I regularly swap off between this & my Vita.
Vita - Whatever interests me, with a focus on the RPGs.
Also, any games I pick up for the old cart consoles can be game only, not trying for complete on any of those. On the DS I prefer complete but will accept cart only because I waited too long to be picky - with the exception of a few franchises (Zelda, Castlevania, Dragon Quest, maybe a couple more). All other handhelds, the games must be complete. Disk-based consoles also must be complete unless it's a very unique situation - for example, I have Data East Arcade Classics disk-only on the Wii because it's very rare & I came across a copy at Gamestop for $5. I'm still keeping my eyes out for a complete copy (or the case/manual), but I couldn't say no to that. I also have a few Wii games that are missing manuals. I believe all of my PS3 games are 100% complete, and I'd say 99% of my PS2 ones are.