So right now the only one you can actually buy is the Steam Deck, the others are not on sale yet; I'm really excited for the steam VR headset (only if its under 500 euro though) because I wanna try making some VR worlds again (I do have an old Oculus Rift but its such a massive hassle to set up and it needs Facebook cameras); however I don't think a VR headset is ever a good idea as a primary game system. The Steam Machine I suspect will be around 1300 euro by the time it arrives and its unclear when that is (I don't recommend waiting for it - you can replicate 95% of what it does using an any gaming pc/laptop running
Bazzite)
I think you are best sticking with the Steam Deck (I have an OLED one); its a great device, although it is getting a touch old now so best for emulators, older games and indie games. They only sell the newer OLED model these days, so if you want the cheaper LCD one you have to get it second hand; however I would suggest even if you're on a budget, get the OLED one, its really a huge jump.
There is a thread for it here:
https://forum.melonland.net/index.php?topic=1381.0*edit:* Also to explain screens! OLED is a newer and all-around better screen technology than LCD. On the OLED Steam deck the screen is bigger, the contrast is vastly better, the colors are a lot better, it uses less battery; and since so much of your game-playing experience is looking at the screen, all that has a huge impact.
I'd suggest looking for a second hand one in good shape, it will save you a bit of money and there are a few out there depending on where you live!
*This has been your Melon Tech Tips report*