I'm a firm believer of language immersion as the best means to pick up a language, quickly. I come from an educational system which leaves the overwhelming majority of students incapable of conversing on even a basic level in Irish, after spending 13-14 years of studying it due to lack of real immersion.

I'm curious as to what people feel is the most effective method of teaching a 2nd language through school? What methods do you feel are redundant, and what do you feel require the most weight?

I think that learning a language in a classroom is a mistake. It's better to teach yourself.

I think that the students have to want to learn. Irish students don't want to learn Irish, so they don't (tá eisceachtaí gan amhras, ach an fhórmhór atá i gceist). German students really want to learn English, so they do. No matter how hard you try, you cannot force a group of students to learn a language, merely provide the education for the ones that want.

And yes, immersion is by far the best route. I was immersed in Irish and German for three weeks at a time, and it did wonders for my skills in both languages.

A classroom setting is maybe, but self-learning is also a bad idea. It works, but it's very slow. I think the best method (barring full immersion) is one-on-one tutoring. That's how I'm learning Mandarin, and I doubt I would have gotten very far yet without it.

When you teach yourself you can set your own pace. You can learn much or little as you want daily.
Tutoring is great, but can be expensive.

Yes, but when you set your own pace there's the temptation of slacking off. I'd rather have a set amount of time so I can study hard during it.

That's true. Self-study requires strong motivation & determination.

I think the best way to learn a language is by being immersed in the culture and having a one on one tutor. Self teaching is fine, and I do it a whole lot, but I think that if you want to be able to communicate effectively, especially with speaking, having someone to practice with is very important.

Indeed. However, you really don't need a private tutor for that. If you live in an area with speakers of your target language you could just go out talk to people. If you don't live in such an area, there's Skype & instant messaging.