It depends really...I have generally found Japanese animes to have more 'feeling' in them. If the subtitles are of good quality then I prefer watching in Japanese. However sometimes get tired of constantly reading subtitles while the anime is on...the focus goes out of the beautiful scenario the anime offers, and I wish I was watching in english...but that's like after hours and hours of watching. Also if I start watching an anime in english, I prefer to keep watching it in english till the end and vice versa
The anime that got me 'into' anime as in saying made me want to watch 'more' animes is Gundam Seed...I watched Gundam Seed Destiny, wing and 00 following that, then I began watching non gundam ones...fma, code geass, naruto, death note and so on...