I think the "perfect agent" is different for everybody. So to be the perfect agent, you just gotta be flexible and give your clients whatever they are asking for and always make it seem like it's no big deal to pull it off. I've only bought houses, not sold, so my experience is limited to that side of it. I imagine the realtor is of much bigger import when selling that buying, unless the buyer is foreign to the area.
When I've searched for a house, I typically would find the ones I want to look at online, then tell my realtor to set up the showings. Like Mike said, the biggest thing was simply having them around to take me to look at houses when I wanted to look at them, which was often and to see a ton of houses. I didn't need very much in terms of recommendations or how to look through some problems to see what could be fixed and improved.
I'm sure there are tons of other people who don't want to do any of the up front legwork. They hire the realtor, expect the realtor to find the best houses to see, and then walk through them and decide. Probably need some hand-holding in terms of information about the neighborhood and what might be good or bad about the house as well. This would almost definitely be the case for anyone relocating who doesn't have the luxury of seeing tons of houses and doesn't know much if anything about the area. I've never done it, but I imagine a good realtor is worth their weight in gold to the buyer in that scenario.
Ideally for me, I'd like if buyers could not even have to use realtors but be able to set up appointments with the listing agent. Then just use a realty office or lawyer to draw up the contract, and save much of the 3% fee the buying agent gets (not from the buyer, it's from the seller, but that would still trickle back down to the buyer).
Good luck! Do you have an agency lined up to join or gonna be out on your own?