In preparation for our trip to Germany (among other places) in May, I've been studying German. I'd studied it a bit in High School, and spent a few weeks in Germany, but I didn't remember much. I've gotten a bunch of different books and recordings, and I want to give a plug for the Pimsleur language tapes. (I'm going to keep saying "tapes" because I actually have cassette tapes from the library, which works out well, because I don't have a CD player in my car.) If you think you suck at learning languages, or just have lousy study skills in general, these are the tapes for you. Most of the materials I've found require that you apply some kind of effective study skills to the material. They present some vocab, some grammar, a few dialogs, and maybe some questions, but it is up to you to figure out how to learn the material.
The Pimsleur tapes do it all for you. You just listen to the 30 minute tape and reply to the prompts. (Prompts are mostly in Engish in the earlier lessons, and move to being more in the target language at the end of Level 1.) If you got confused, listen to it again - but not right away. Give the material at least an hour to digest. If it is really tricky, pause it between prompts to give yourself a chance to think, but ideally then do it a second time later without pausing. (Because with a language, you really haven't "learned" it the material until you can reply at a reasonable conversational speed.) You really and truely just listen to one 30 minute tape a day, and that is it. (I looked up some additional information on the grammar, just out of curiosity, but if you aren't curious, I don't think you'd need to.) Each level is 30 lessons, and unless you are an exceptional language-learner, I doubt you'd find any other method that gives you better command of the language by less than 20 hours of effort over one month. I'd guess that the full series of three levels covers about what you'd get in a "German 1" textbook, but without the reading & writing. They have little booklets with a bit of practice reading, but it is almost entirely oral.
Unfortunately, each level is $350. Over $1000 for the set, and that doesn't get you past basic small talk. Way more than I'd be interested in spending. But I actually feel pretty confient about the material, without stressing out or trying too hard, and I'm pretty language-impaired. You do have to actually do the tapes nearly every day for it to work, but that is more a matter of actually making the commitment to do it than any actual effort. So while I can't say I'd recommend spending that much money, I totally recommend looking for the tapes through inter-library loan.
After that wonderful experience, I found a copy of Rosetta Stone German 1 software at Mike's house. That is a whole different thing. They have an "immersion" approach - no English translation, no explanation of grammar. No explanation of anything. (Pimsleur offers occasional bits of explanation of grammar, though not much.) They have pictures, and you just have to guess. They do a lot of multiple choice where only one answer makes any sense if you understood any of it. (Like picking which picture matches "The woman has three plates." when only one of the images contains a woman, plates, or three of anything.) The lessons combine reading, writing, speaking, and listening - not strictly oral like Pimsleur. The voice recognition is not perfect, but it is very cool.
Judging by the pace of the first few lessons, I suspect the full set of five programs covers approximately the same ground that the three Pimsleur sets cover. I could be totally wrong on that - Maybe they pick up the pace later on, but the early lessons cover extremely little material. The full set of five programs is $750 (on sale for the holidays at $600), but you can get the previous version of the software (which is what I have) for under $200 from other retailers. I might actually buy that.
Third recommendation is for the "Before You Know It" (BYKI) flashcard software. Memorization is my downfall with so many learning endeavors. BYKI is strictly flashcards - often with pictures and audio. They have a free version, which is quite good. You can download user-created vocab lists, which are very good for popular languages (less good for obscure languages). The deluxe version is $50. It gives you more porfossionally created content, the ability to create/edit lists, and a few more activities. For straight-up vocabulary cramming, it is great. I've mostly used it for Sanskrit, but I'm now checking out the German material. Highly recommended.
-- Joshua