Do you want looks or practicality?
Best 125 is the RS125 imo, derestricted to around 30hp (a bit naughty though

), but its unreliable as hell.
Most practical 125 is the cg/ybr. Look s**t but bulletproof and cheap. Tried and tested, brilliant bikes.
Reliable, good looking bikes, imo, are the hyosung gt125r or the yamaha r125
A bit of an adventure style, comfy, reliable bike, honda varadero 125. I had one of these, will sit at 80, mine was on nearly 30k when i sold it and never had a problem.
But if you plan to get a licence, go for a cg, buy it, ride it over winter, do your licence, sell it in spring for more than you paid now. Thats the sensible thing to do, not that anyone ever does it lol
Best advice, dont buy new, the dealers will tempt you with cheap/free insurance and kit but its just not worth it.