which tax software is good for a nwew tax professional who is wanting to do tax returns unlimited ?

You could try Pro Series Professional

Depends on what you you are looking for.  How complex are the returns that you are planning on preparing?  Is money no object or are you looking to get by as cheap as possible?  The best thing to do is shop around to see what programs are out there in your price range and then contact the companies to get copies of last year's software and give them a test spin.  For myself and for Mt Juliet, we both made the decision a few years back that ProSeries gives the best bang for the buck.  Since you are posting to a Lacerte forum, I'm sure their users will give you the same opinion about Lacerte. 

Good Recommendation IRMN

That's like asking which is the best car, Dodge, Honda, Chevy, Toyota, VW, Ford, Nissan, or (not) Subaru. If an obvious answer  existed, only one or two programs would be on the market.  But ProSeries is a safe choice.

I like the pay per return feature of ProSeries for those who do not do enough of any particular business returns to warrant the full blown program. Also, with Pay per Return you can get the software for any state even if you only prepare one or two returns from that state for a reasonable price. Pay per return may be a good choice for someone just starting to build their practice as well.

Lacerte also has the pay per return feature.

Lacerte also has the ability (which I suppose ProSeries may also have?) to mix-and-match "pay per return" with "unlimited."  For example, I have unlimited 1040's, and the states of PA and NJ, while I pay for each return of, say, South Carolina, North Carolina, New York, etc.  I also pay for each return of the 1120, 1120S, 1065 and 1041 programs.

The pay-per-return price is lower for my South Carolina individuals than the individual pay-per-return would be if I had not bought the 1040 program on an unlimited basis.

 Lacerte's pay-per-return deposit minimum (only applies if you don't license at least one program for unlimited use) is high enough to price some people out of the market.  One of the CPAs in our practice group switched to Drake because the REP deposit was more than the pay-per-return fee for all the returns she does.  She's mostly-retired, so does very few returns.