First ... based on the bottom leaf damage on 2 of them it looks like they may have been overwatered but are doing better. As for the shriveled plant ... if they're all the same strain and a thorough watering doesn't bring it back, it probably wasn't a viable seed. You know there's a reason for the bumper sticker "shit happens" ... not your fault.
Personally, not a big fan of solo cups. I think these
RootMaker Propagation Trays are the first and most critical step toward creating a fibrous root system. RootTrapper II Containers prevent root circling by root-tip-trapping, which stimulates root branching. Includes One RootMaker Express Tray w/ Cells & One 3, 5 & 7 Gallon RootTrapper II Tall.
myrootmaker.com
are the best starter pots for photo period plants ... but to each their own.