Well,for me, the best ROM is Ruby or Sapphire.
They have nice music how in emerald, nearly the same functions as emerald, but no animation of the Pokemon.
But the best point: much space. You have enough for the whole hack
(there are some exceptions maybe)
diamond and purel cuz i can put it onmy r4 and play it evry ware i want
but its realy hard to hack it i gane try now my furt time but din't make a hack in my hole live so gueass it will be verry tuf thing for doing that :o
I can still remember the day I bought Ruby. After a save file that lasted over 360 hours, I finally ran out of things to do. About four years went by until I found the game again, and using my "older boy" knowledge, ripped the save file after building an Xboo cable and started playing again on my computer. Then I decided that I wanted to make the game better. So, I started hacking and inproving a lot of little things and before I knew it, well, I stopped fixing things and started adding to the game. I've always played Ruby and I now I always hack it.
I personally prefer to hack Emerald myself, I like the visuals and music of the game a whole lot more than FRLG, and the FRLG music is in there anyway. The in-game clock also makes it simple to implement day/night cycles, which I could never get to work with FRLG.