Since I use almost all paid plugins I don't feel the need to thank anyone - I did the thanking with my wallet.

As far as the free plugins I use - most of them are so cluttered with ads and crippled in some way or another - again I feel no desire to thank them. I consider them thanked every time I don't nuke their crap plugin and endure their advertising.

Everyone makes money from WP in one way or another here.

I'll just say thank you to my bank account. :)