Jeanie's bottle, no doubt - it's the gift that keeps on giving. Need a lambo? Blink, there it is in your driveway. Need a burger and fries? Blink, there it is on your table. Who the hell would need anything else?
The portal gun is a neat idea, but considering you can only have 2 active portals at any one time - and you travel to the place where you want the second portal anyway, it seems kind of pointless.
I mean wake up, zap a portal in your closet, fly all the way to wherever you want to go and zap another portal, The only upside is that the trip home is instantaneous. To use thailand as an example - how many times could you travel there before getting bored? Or anywhere for that matter? The fact that you have to get to where you want to go before you can go there, makes it pointless.
Though if you want to have fun - zap a portal in your toilet and one over the bed of your enemy :lol. Or one in your living room and one in the playboy mansion :love.