Where money is no object!
Longest lasting , no puffing, best warranty ( yeah, I've read one battery company does give one), most power etc.
I've read a lot of Lipo shootouts but on these forums I feel it would be the Racers that could give the best advice.

yeah because us non Racers use hamsters to power our rc,s

Joking aside even if I had the big bucks I would still be using SMC and Turnigy lipos. I have used more expensive lipos in the past and the only place I see a difference is in my wallet.

Edit
Im speaking on 2s lipos I have used past/present
I have 1 4s smc lipo and so far so good.

This is just my opinion from having actual experience from using these items:

Smc 6s 4300 - purchased (3) of them for my buggy because I run a 1350kv motor. 2 have dead cells and one is super puffed, last one still working but there's always a cell that is a few volts behind after full balance

Maxamps 6s 4000 - have (3) as well. have changed absolutely nothing in my buggy except for the batteries. These batteries balanced out every time and go into storage mode every time. They do have more punch. These are in soft packs and no sign of puff.

I use the same methods to store and balance so everything remained equal Throughout. Race 3 times a week, Friday, Saturday and Sunday and medium to large tracks. Even wicked weekend and fall brawl.

I can actually Agree with the Turnigy batteries. I have 4 of the Ultimate Nano Tech shorties and literally abuse them and they haven't puffed or lost any power. I have a Team Trinity White carbon stick that I hope lasts due to it's awesome power output . I bought one of the Graphene packs and it puffed after a couple of charges. My latest is the Reedy Zappers 7.6v packs. I don't have a charger that will charge them to that voltage but they seem to be doing fine after many charges. Maybe it's because I don't peak them out on the voltage. The Orange Revtech batteries all have puffed after a few charges and will no longer Balance. This is my experience so far.

I'm actually thinking the charger might have a lot to do with the battery life. Currently I have a Hitec X4. ( the first one out) not the plus