Spare cash, suspicious of ISAs.

My partner and I are both self-employed in the creative industries, own our home, and have no kids. We sold a house in 2007 (clearly a huge mistake) and because we maintain a reasonably inexpensive lifestyle, we have since then had about £200k sitting around in a current account where it isn't even fully protected by the government guarantees. We never did anything with it because I had a horribly negative experience with some sort of tax free investment account which to date has made me two hundred quid in fifteen years, and absolutely wasn't worth the time I spent setting it up.

As such we have no idea what to do with this cash. I'm not particularly interested in the most common investments people make as I'm deeply suspicious of how they really work, and I've seen that they don't work at all for joe average. I'm well aware a couple of hundred grand is nothing in the grand scheme of high finance. I have no great objection to leaving things as they are and we need some funds available to do things like pay taxes, but it'd be nice to at least keep up with inflation.

What do we think?