The collector trend from social media seems to be vast but here are generally what people collect for

1. Complete set collector for specific system (WiiU, Vita, switch & etc)
2. Collect only their favorite franchise. They want to get every game release, variant and memorabilia
3. Rare title that worth money from various system. IE: PS2 collector constantly display rule of rose, haunting ground and ku-on as their rarest games that worth money.
4. LGR, strictly limited, and many other limited release games
5. limited version console/handheld. Some collector aiming for complete N64, DS, 3ds and etc.