I think SSDs are worth it. There are three Samsung SSDs working in my PC right now, because the upgrade from HDD to SSD is (at the moment) the only upgrade that is really noticable. You get more out of those dollars spend then, lets say, investing the money into a better CPU, GPU or whatnot. Just look at those benchmarks: http://www.anandtech.com/bench/product/1121?vs=966 for example. A SSD lets your system boot faster, lets apps be snappier and of course also shortens loadtimes for games.
One thing tho: SSDs get slower when they are nearly full. Any modern SSD with 128 GByte will get slower if you go over 100 GByte of Data as a rule of thumb.
They have less space than those old HDDs but do you really need 1 TByte? I've got a NAS for all images, videos and music. Steam has my games only one click away. Then again I'm on 100 MBit fiber and they are downloaded to my PC in only a few minutes, so your mileage may vary.