I completed the Regional Dexes in Pokemon Gold/Silver/Crystal, Pokemon Diamond/Pearl/Emerald and X/Y. But I can't be bothered to get all the Pokemon from the previous versions to complete the national dex. You can't just catch them in game anymore and have to import them. So I just didn't care and only got stuff I cared about. Plus the event legendaries are just ridiculous to get legitimately.

I never thought of the idea of catching them all, really. As a kid, I thought that 151 were too many. I thought the idea to be TOO bothersome.
Now that I'm older and there's 718 different species of Pokémon, I immediately regret not having done it when they were only 151.

Oh well, still got my favorites. Go, Fighting Types! =O

Nope, I only catch ~20 Pokemon per game.

Too lazy to catch 'em all.

Close, but no cigar.

Only in Emerald, since then not in a single pokemon game. Might try it in X / Y again though.

Ain't nobody got time fo' dat.

Meh what was the reward anyway? Only caught favourites too.

713.  I am missing Jirachi, Shaymin, Arceus, Meloetta, and Genesect.

Closest i ever got was in sapphire version. Was a chimecho away from completing the dex

I know that feeling.  I spent years being a Corsola away from completing it in Pearl.