i recommend the Madison and firehole. they may be doing some work on the gibbon.
take a hike up a small hill and fish trout lake for nice cutties
also, if you don't mind hiking and have a float tube handy, Grebe Lake can be fun. they have artic grayling there.
don't be scared to fish the Madison outside the park. could catch some stoneflies.....between the lakes is good. 3 dollar bridge
stop in and see Kelly gallup at slide inn or MRO or Blue Ribbon are all good shops in or near west Yellowstone
enjoy your trip...if you have extra time go fish the green river in Utah and you might hit some late cicadas