I can't really say. I always go to StubHub first, but that is primarily because that is what I have experience with. MLB has switched over from StubHub to SeatGeek as their official ticket reseller starting this year, but I'm not sure how many sellers have actually migrated over. I tried listing a couple games on SeatGeek, but I didn't like the options. For example, my tickets are on the aisle but I couldn't find any way to indicate that on the listing. My tickets sat unsold on SeatGeek for awhile, so I pulled them and sold on StubHub instead. I imagine the inventory will start to shift more toward SeatGeek over time, but I don't know how much of it already has.