I started my system with the good old GE/Jasco switches, I tried out one of the Eaton and i was not impressed with it. If push comes to shove, I can live with it, but I was wondering what people are using these days…
Also, I’ve been trying the Kasa ones and I like them, but for consistency’s sake I’d like to stay in zwave if possible…
i would imagine the three top z-wave brands are jasco enbrighten, zooz and inovelli. @jdroberts will come along and give you much more info 
personally i love lutron caseta but they are not z-wave
I figured Enbrighten was the rebrand of jascon, since the packaging is identical…thanks!!
In terms of US sales, GE, Leviton, and GoControl are likely the most popular. In this community, Zooz and Inovelli are also very popular because they are small companies which use the latest technology and offer budget prices. And both have company representatives who are active in this forum. 
Homeseer have also been popular in the past with power users because they offer Some unique features like tiny LEDs that can be set to different colors to use as indicators.
Every brand has pluses and minuses and its own unique features. And different people have different needs and preferences.
I personally like the style of Eaton Cooper, but these days I would probably go with zooz or Inovelli because those are the two companies that have shown the most commitment in keeping up with all the different platform changes that smartthings has gone through in the last few years. So I feel more confident that those are the two that will continue to work well with smartthings in the future.
The SmartThings Custom Code Requirement
As you may know, smartthings is in the middle of some major architecture changes for their cloud and platform, and they haven’t yet detailed exactly how and if custom code will work in the future.
This has been annoying to some of the device manufacturers since the whole point of zwave from their point of view is that as long as their devices are certified, they aren’t supposed to need to do anything special for different Z-wave hubs. But smartthings has its own abstraction layer (that’s what DTHs are) and so quite often switches which worked just fine out of the box with most other Z wave hubs require special code to use their features with smartthings which add time and cost for the manufacturers.
Homeseer and Fibaro have already indicated that they are not going to put any effort on their side into meeting the special smartthings requirements. Their devices are Z wave-certified, and they feel any unique requirements should be the responsibility of the hub manufacturer. But Samsung feels it should be the responsibility of the switch manufacturer, so it just isn’t getting done for those brands.
Other Protocol Alternatives
I personally use Lutron switches. As @jkp mentioned, these are not Z wave, they use their own proprietary protocol. Really well engineered. But I use mine through HomeKit and Alexa. Although there is a smartthings integration which was originally created by smartthings a couple of years ago, I don’t feel I can recommend these for smartthings at this time because neither Lutron nor Samsung seem to be committed to maintaining that integration. 
For example, the fan switch came out almost 2 years ago, but has never been added to the integration and each company says it is the responsibility of the other one to do so.
There are some other companies with other protocols who are creating their own smartthings integrations, particularly some of the Wi-Fi device companies, so you can certainly look at those as candidates.
The biggest advantage to going with Z wave light switches is that then you get a lot of Z wave repeaters through your home which improves the performance of your smartthings zwave network.
Back to brands
Can you tell us more specifically what you didn’t like about the Eaton switch? Then we might have a better idea of what other brands would work for you.
And meanwhile, you might take a look at Zooz and Inovelli if you’re willing to look at devices from smaller companies. Zooz is the house brand for The Smartest House online store.
And here’s Inovelli
They are getting ready to discontinue their “inovelli black“ product line so there is a big sale on those right now. They are going to emphasize their “Inovelli red“ product line for the future.
Both these companies offer excellent technical support and can give you a discount if you are buying in bulk, so that’s another plus for them.
Historically Inovelli has occasionally run out of product until they get ready for another factory run so they have sometimes been out of stock of popular models for a couple of months. That has not happened as often or for as long with Zooz. So it’s just something to be aware of when planning projects.
If you want something you can pick up at your local Home Depot or Best Buy, then Leviton or GoControl or GE Will probably be your best bet.
Regardless of Brand
Whatever you get, these days I would recommend getting models that support the latest Z wave features, which is “series 700” instead of “series 500”, and which support the latest security features, S2.
However, there’s a caveat: if you intend to use zwave direct association, all the devices have to be at the same security level, which could complicate things if you need to include some of your existing Z wave switches. If you don’t use direct association, then don’t worry about this at all, you can mix-and-match generations just fine.
THE INDICATOR LIGHT ISSUE
Does it bug you that this is the only header in this post that is in all caps? If so, you’ll probably want to know about this next point. 
Your existing GE switches should have blue indicator LEDs. That’s what most companies use. Leviton, however, uses green. Many people like to make sure that the indicator LEDs match color for switches in the same room, and some people like them to match color throughout the house, so that’s just something to be aware of. Other people don’t care one way or the other.
Well, that’s more than enough for now, I’m sure. Can I ask why you didn’t just get another GE switch to begin with? Again, that might help us make more specific brand recommendations for you.
Yes Jasco OEMs GE, Honeywell and a few other switches. They also recently bumped the warranty (retroactively) for all their devices to 5 yrs.