The problem is that the OP's question has three different lists based on performance, consumer value and profit for the manufacturer although there are a few cards which might appear near the top in all three lists.
Performance list as follows:
8800GTX - just because it was the faster card for almost two years which is unheard of really. At the time of release it resoundly beat ATI1950 xt in xfire which was fantastic for a single core card and we will probably never see that day again.
3dfx Voodoo1 - The start of 3d gaming on the PC and I even today I have never been as blown away as when I first got my voodoo1 card. Again perhaps we will never see such a big change in computer graphics again. Quake and tombraider were memorable.
3dfx voodoo2 - Is worth a brief mention due to the massive leap in performance over the voodoo1 plus it introduced SLI so you could run two voodoo2 cards in your rig for extreme performance (Nvidia didn't come up with SLI btw

)
9700Pro - Was a long way ahead of Nvidia at the time and ATI were miles ahead on image quality and Nvidia didn't catch up until the 8800GTX.
x1950x - Worth a mention due to it's new techniques and memory controller and it's sterling performance.
Consumer Value eg Bang for Buck
8800GTX - despite being the most expensive card every released at the time, the fact that even today people are still using them fine gives the card such good longevity it has to be in the list. Of course a crystal ball is nice as at the time of launch there was no way to tell that a few months later ATI wouldn't come out with a much faster card for less money (which they didn't of course)
8800GT - A steal. A card almost as fast as the 8800GTX but for only £130 which sold out with 24 hours. I sold my 8800GTS 320Mb a week before for £145
4870 - A card which could complete compete with the gtx260 yet cost £100 less. This forced Nvidia to slash the price of their high end cards. Worth being in the list just for that reason.
Geforce 2 MX - A cut down card but mega cheap and gave great performance and sold by the bucket load.
9500pro - just cause it could be soft modded to a 9700.
3dfx voodoo1 - Only cost just over £100 from memory and for a card which totally changed the world of pc gaming like no other, it was quite cheap too. However, we didn't think so at the time but we didn't realise high end cards would soon cost £400.
Profit -
These are never going to be the high end cards as all the profit lies with the mid and low range cards in recent years. However, in the early days it was different.
Voodoo1 & voodoo2 - Made 3dfx so much money that they regularly blew £25,000 on lunch
I can only make a guess for which low/high end cards made good money. The gtx8800 cost £400m to develop and wasn't a cheap card to make so may not have been the most profitable for Nvidia.