It depends on how much area you want to cover, but generally I prefer a top feed (gravity) HVLP like the one pictured above. Always load enough material to get your job done without a refill, as its best for paint leveling to get the whole job done uniformly.
I use anything from a small air brush (Iwata NEO TRN-1 and for really fine work an old Paasche side cup with a really small tip) to full size HVLP units (DeVilbiss ITW Tekna) or a smaller Devilbiss spot repair gun. These are both HVLP gravity feed. You can buy other brands at nearly 1/10th the price of the DeVilbiss but for seriously great results, the price tag is warranted. Pot feed units are really for shooting upside down, or in close quarters where the paint cup is remote from the gun itself.
I also have some older siphon feed guns - even a nice little pint cup one from Sears - that work well. I find the siphon feed can achieve better atomization simply due to how it mixes sprayable material with air. But generally HVLP is the way to go.
Edit: yes you are right, pot fed systems do waste a lot of material. I only used them a couple times to paint aircraft interiors where space constraints dictated their use.