Most of the Famicom discussion would probably take place in the
Import-Mania sub-forum. Additionally,
Famicom World is a great place for Famicom discussion, as you can imagine, although the emphasis on pirates over there bores me a little.
I only have 29 Famicom titles, but I'm slowly trying to turn most of my NES collection into a Famicom collection. The carts are smaller and take up less room and generally censorship on NES carts makes the original, authentic cart more desirable. Plus, as you mentioned, the tons of early arcade ports are a must-own: Dig Dug II, Mappy, Nuts and Milk; and that's not mentioning the Japan-only shooters like Parodius (although those in PAL territories got a release, NTSC-U did not) and Gradius II.