I vote for LCD. Although they are generally more expensive. They do in fact have a longer life span and less prone to problems like plasma experiences. LCD also aren't more clear than PLASMAs, they have similar picture quality. Go for the big brands like SONY, Samsung and LG (famous for LCDs). PLASMAS also use more energy than LCDs and even CTRs (the fat old ones) being less environmently friendly and making your electricity bill more hectic. Overall, you should choose an LCD (the size will depend on the size of the room it's going to be in). However, if you really rich and want something stylish and thin look for LED tvs if they have arrived in Germany yet (most likely).
If you buy a tv with no hd tuner you need to buy a separate tuner and set it up on your TV. You might have to adjust settings but there will definitely be a guide. I recommend you buy a tv with build in hd tuner because its more convenient and mainly older TV models don't have hd tuners (its up to you). However, most TVs lcd or plasma do in fact have built in TV tuners. I personally don't like the HD channels in Australia. However, i don't really know about where you live.