There are very few details that look out of place, you've done such an impressive job with everything. I think your top image is completely realistic, really amazing work. I do agree the seeds seem a bit large in your second scene, but the texture work and lighting is fantastic. The third scene is beautiful, especially the concrete, it seems like one of your leaves may be intersecting another, but honestly that may just be me. Very inspiring work!
You are very welcome and good to know it was just me on the 3rd one. I really admire the level of work you put into your pieces and can appreciate the expertise it takes to get the textures right, especially the mapping (nothing ruins a scene like poorly mapped edges). Keep it up, it inspires me!
WOW ! This is Amazing ! How long did you spend to arrive at this level ? I did you this question because i want to learn 3ds max ! But i don't now how ... If you have some guides or tutorial on web, please link it to me... What would be gr8 !