I'm interested in hearing what people think a dream language learning app would look like – tossing around the idea of getting involved, but mostly just fascinated by the pedagogy here, and with how strongly people seem to feel about one program over another.

I've always thought the Rosetta Stone immersion system (of only seeing the target language) made sense, but people seem to prefer systems that feature both the native and target languages – is that because RS is flawed in other ways, or because having both languages works better?

I'd be grateful if some old hands at language acquisition could walk me through what their ideal system would be from beginning to end - what existing systems would it borrow from, where would it add more depth, and what new techniques would it incorporate?

Thanks so much!

I'm learning Japanese with a combination of a grammar guide - Tae Kim's Guide to learning Japanese - and Rosetta Stone.
RS really is a good program, but I don't like learning languages without knowing anything about the grammar.

I've never used RS myself but the general consensus seems to be that it's nothing but a colossal waste of money and that the so-called "immersion" side of it is nothing but a gimmick.

It's good to get a feel of how the language basically sounds and feels like. But it's only a basis from which you can develop. Sure it's really expensive, and I don't really know if it's worth the price, but if you have a chance to get it, just try and decide for yourself. And I also think you can use it efficiently without a grammar guide of some kind (but I think I mentioned this before).
But you also don't learn a language by just learning grammar and words. You have to learn sentences. Not to translate them, but to understand without translating.
Just my opinion.

Ah and a bad thing about RS (Japanese) is, that they speak veeeeery slow. I don't think you will meet any japanese person speaking this slow

There's also another page for learning with dynamic imersion. It's called live mocha and large parts are free. It's not as good as RS though.

It might be worth seeing if you can loan one of their titles from a local library.

I've been teaching myself Irish on my own on and off for the last several years. So far, the only sentences I can speak with any real fluency are those included on my Pimsleur CDs. I only wish I didn't find audiolingual methods so unbearably tedious.

immersion is the closest thing to a 'Perfect Language-Learning Program' in my opinion