You noticed that the EVGA and MSI are Ti versions which is slightly faster than the regular Gigabyte?
Also, the EVGA link opened a search result site instead of a product site, showing other brands and models as well. No big issue, actually vice versa since it shows the pricing variety for basically the same card of the same brand.
If, as it seems, a GTX1660 (Ti or not) is the one that fulfills your needs and fits your budget, I'd say that basically any of those or similar products from other big names should do. If you prefer one brand because of positive previous experience, there's no arguing against that. The following list (in no specific order) might help choosing:
- Connectors: Obviously you'd want your monitor to be connected without any adapters. DVI, HDMI, DP? VGA may already be outdated.
- Backplate: Some models have a metal backplate and it can add stability especially with the longest cards.
- Fans: Large fans create less noise than small ones. Two fans of create less noise than a single one of the same size. One large fan can be quieter than two small ones. Fan blade design not only affects the noise level, it also can tune the pitch to an irritating whine or a tranquil hum. Some reviewers take that into account, so do your homework.
- Size: As you've noticed there's both long and short ones. They're equal in performance so choose according to your case. Triple fans are of no use if there's no fresh air around them.
- Coolers: The reference model has one fan at the end of a box and it's both inefficient and noisy, all the models you've referenced to are modified. Check the manufacturer's specs and study some comparison reviews if needed.
Choosing the right one from within the variety of a single brand is a lot like choosing the right lure for the next fishing season. The fish don't know about fashion, it's all about fulfilling the dreams of the fishermen. It's the same with video cards. If you've got enough power to provide a stable high frame rate and a decent cooling to keep the card alive, adding a heat pipe or overclocking won't make you any better as a player.