Thanks for the replies everyone! I think one of the main reasons I was out of it for so long (that I didn't mention) was that my PS3 kicked the bucket ages ago and I didn't buy a new one until late last year, ironically I actually have all the KH games listed (minus chains of memories) included 1.5 and 2.5, because I knew I was going to get back into it eventually, but I was overwhelmed on where to begin xD

So should I just go 1.5 --> 2.5 --> and then 2.8? Is that the most efficient way to do it?