Well, here is one more opinion to thoroughly confuse you.
Your interests are macro, wildlife and landscape.
I think the 15-85 EF-S is a better all-around walkabout lens outdoors. It's a 24mm equivalent at the wide end, which is wide enough for 90% of the time. It's a 136mm equivalent at the long end, which is handy when outside and you need a bit longer reach and don't have time to change lenses. With this lens, you may not need anything wider for quite awhile.
It's slower than the EF-S 17-55, but as sharp and solid. Kind of a tossup between the two, but if you don't need the faster speed, it's a less-expensive equally solid performer.
If you are interested in wildlife, I would skip over the 70-200mm lenses. They don't have enough reach and I'm not a tele-converter fan. I haven't tried the 70-300 L, but I understand it is a great lens and very sharp. A bit slow though (f-stop, not focusing), but that's the price you pay for longer reach. It is a bit expensive to my way of thinking and hard to come buy on the used/refurbished market, probably because they haven't sold all that many yet.
The 100 L Macro is a fantastic lens. If you have any interest in macro, it's a no-brainer. Worth every cent and the IS makes it very useful for portraits, short telephoto shots, close-ups etc.
If you are seriously into wildlife, don't rule out the current 100-400. It's regularly available on the Canon refurbished site if you are in the U.S. When and if a new model is finally released, I expect to see the same price inflation that we've seen with other new Canon lenses, so unless you're prepared to go well north of $2,000, I'd consider the 100-400. I rented that lens, the 300 f4 and the 400 5.6 at various times. The 100-400 is the one I decided to buy.
If you do decide to eventually go extreme wide-angle, I like the Tokina 11-16 f2.8. They have announced an updated version that won't be available until late summer. Tokina makes very good glass. The Canon super-wide EF-S is supposed to be a fine lens as well, so no criticism there. I just like the Tokina better.
Finally, I wouldn't take my advice or anyone else's without first going to the LensRentals.Com site and reading "Roger's Take" on the lenses. He knows this stuff better than anyone here does (and since he rents every lens, he's tried them all.)
Personally I think the biggest dilemma is choosing the right telephoto zoom, because there are so many choices out there.