Just a reminder: versions displayed should be 16 x 16 pixels and 256 x 256 pixels for each entry
And don't underestimate the importance of the small 16x16 pixels format. That is how the logos are presented at coinmarketcap.com. It is also a good indicator if the design can withstand scaling and if it is recognisable from a distance.
Imo the best way is to save them as png with transparent background. Then you have the logo only without extra hassle. I think the logo should be appealing as a logo only in it's pure shape and form without extra graphics flashy texts etc. This is why I did the comparison table and I will update it when I can.