We had problems with Omron inverters, they change the manufacturer and now the new inverters doesn't fit fisicaly and the paramenters order are different too. I need to make a decision and select wich brand is better for my company. Righ now Yaskawa is my better choise. But I want to know your opinion.

Opinions differ widely, and this may change in 6 months, however right now I would rate inverters as:
1. ABB
2. Siemens
3. AB

Baldor is pretty good...

They usually come with ethernet(modbustcp)/usb/serial

Had good luck with AB, Baldor and Toshiba {several years ago}.

If you were using Omron, then Yaskawa should be familiar since they used to make all the Omron ones.

ABB and Mitsubishi have good inverter lines as well.

I would say SSD for me.

Although to be realistic i would really say whoever gives the best support in your area...

I love the ABB drives...

But I'm going to go with 504bloke, its the one that has the best support in your area and thats going to require some legwork on your part. The best inverter in the world is worthless to you if you can't get it and/or there is no support in your area.

I like most of the ones mentioned but recently started using AB Powerflex drives. You can literally connect them directly to the PLC with Ethernet with no control wiring at all.

My control wiring consists mostly of using the enable inputs to perform STOP functions where I need a non-PLC controlled stop. The Safe Off function of the PF 70 and the PF700S is even better since it's essentially a fully redundant safety relay version but on the job I'm doing now, I don't need quite that level of safety so I went with the much cheaper PF 40's with Ethernet boards for all controls except for the stop functions that have to be external to PLC control for Code reasons.

From what I've heard, Toshiba really shines in medium voltage applications.

Baldor is the best inverter you can find in the market today. There are designed for all kind of environment and some of them coming with internet capability.

I like:

ABB
Mitsubishi

AB 1336 Plus series drives were some of the best ever built. I worked in plant for 8 years where 500+ of these units ran 24/7. Very few failures, unfortunately most of the 1336 series is discontinued.
The Power Flex series is alright
Don't like Baldor much, good drives not a configurable as AB or ABB (at least not the units I worked with)
ABB is solid.
Had a boat load of issue with ACTech. (might be AZTech)

I use Zener Electric. Who? Aussie of course.
Danfos have pretty good reputation.

personally I think the aplication dictates which drive is best. I noticed no one metioned AC Tech. For simple start stop with maybe a jog function or 2 you can not beat these for the price. I do like the Powerflex when I am using an AB platform but if it is a Siemens platform I prefer to use their drives. On web handling machines I found that the SSD's were really easy to setup and trouble shoot. I have not used an ABB in years so I do not really have an option of them.

I will say I have one brand I find to be a total piece of junk for the cost and that is the Square D Altivar. This drive in my opinion has the most convoluted comand structure I have ever seen.

Not seen any referance to SEW eurodrive inverters yet.
Dont know if they are availlable over the water, but have a good distribution in UK/ Europe.
Helps that main UK factory is just down the road :)
Also good for setting up as has auto setup for motor if you are using an SEW motor with inverter.
We use these alot and found that they give all the options that we need but have the capacity for lots more.
Nice design as well

The manuals do it no justice either...

Except, if you can read Mandarin, it's a breeze!