My first time through? I chose the Claw Fossil; I find Rock/Bug a more interesting type combination than Rock/Grass.
Neither, lol. I suck at the biking puzzles and often just never got to the fossils. The ONE time I got someone to get me through that tower I picked up a root fossil.. and then never used the Lileep I got from it. So I have 0 experience with either Pokémon.
When I played the game, I went for the Claw fossil. I never used it in the game, mostly because my Blaziken was extremely over levelled.
To be honest I really like both, but Armaldo always calls for me. I like its design more than Cradily's, but both are good.
Used to always go for Armaldo because it looks cool (As a kid, that was all that really mattered, except for raising Gwen too), but now I always go Cradily for the versatility.
The Claw Fossil was my style. Anorith and Armaldo were more offensive, which is what I go for when I play, so the Claw Fossil suited me more than Lileep and Cradilly did.
I always pick Claw because I liked Armaldo's design. Lileep is pretty cute, though. It took me a while to realize that those two glowing dots on top of its head are its actual eyes.
I chose the root fossil in my first playthrough. I remember well that I already knew I could obtain Anorith later by trading. Armaldo is cool and all, but... It won't never be more than a joke of an anomalocaris, so it was a fairly easy pick for me
Claw fossil! Armaldo all the way! I used one in my AS Nuzlocke and it saved me from certain defeat, so it holds a special place in my heart.