I would go against the Golani. I had one and wasn't a fan. First off, it may have a folding stock, but it's actually quite overweight for a rifle of its class, which may be an issue of portability really matters. The mags for it are much more expensive and harder to find than AK47 mags. There are very few accessories available (optics in particular can be a challenge). Quality control on these rifles is pretty iffy, many are satisfied their Golani's and many are not. On the plus side, they have mild recoil and do have potential for accuracy, but the sights on mine didn't seem to hold zero. The folding stock is actually quite solid.
The other two could be difficult to decide between. The WASR's tend to be more prone to issues like roughly cut mag wells. The fit and finish on the Romanian receivers seems to be particularly crude (certainly was on my WASR 10/63), the Polish underfolder in contrast seems to use an NDS receiver which is of pretty decent quality by comparison. However, the WASR underfolder comes with a chrome-lined bore which will help resist corrosion, be easier to clean, and prolong durability. Either gun would accept cheap, ubiquitous standard AK mags and there's a wealth of accessories available for both. The folding stocks on these AK's vary in how solid they are, from not at all, to very much so.
The Saiga .223 would be hands down the most well-made of the bunch, with the best fit and finish and with the most attention paid to detail. It will be the only one that's 100% factory new, made at the same arsenal that's been making AK's from day 1. The rest are a mix of US-made parts (as is required by law) and used surplus parts from their respective countries. It should also be the most affordable, at least in its factory configuration. At the same time, if you want it to be more like a standard AK (with a pistol grip, trigger moved forward, etc) would take spending time and money, so you probably will end up spending the same as on the other options. They will accept some AK accessories but not others. Mags aren't hard to find, but pricier than standard AK mags.
