Senjou no Valkyria, So Ra No Wo To Recommendations
Both are alternate realities with a European WWI or WWII kind of feel mixed in with a little super technology. Valkyria Chronicles is a bit more conventional in its relationships whereas Sora no Woto hints at Shoujo-ai (girl/girl love) but never really goes there. Both are beautifully animated.
Both series involves the military theme and packs action as the episodes drags on. Valkyria Chronicles does have inklings of romance while but Sora no Woto is still something worth to watch.