My vote goes for Desktop computers based on experience and overall logic.
Desktop computers offer allot more cappabilites then laptops, epsecialy for gamers and people who use softwares whith monster requirments such as 3d modeling programs and many other which would immediatly crash on laptops.
Second of all i personally think pc is a better investment,u can change components,upgrade them and when something goes wrong its easy to find out what is lagging and fix the problem, laptops on the other hand are nuisance in those casses,most of the graphic cards are integrated with many other hardware components, fixing them is allot more trickier and lasts longer then on pc's and when they die its permanently.
Also the guaranties for pc's last allot longer than on laptops.
I had a limited edition -special performance MSI laptop,although it was a beast in laptop family i think that it would be better if i have invested in pc.Two and a half years after buying it died,due to many problems such as overheating,fan replacements,cracks on the oppening mechanism and inability to charge the battery(and all of the problems started do show one after another ,after one year of use)
My recommendation is, invest in excelent pc with good performance and buy a cheep laptop with exterior hard disk for extra information