If you consider ethereum and litecoin as altcoins than they are worth buying, they have longterm potential. Never checked ripple before but it looks big so that might be too. If you want more risky ones, nxt and radium looks promising but like I said they are a lot riskier.
I think that Ripple is taking attention of traders and I have a feeling that this is one of the reasons why the ethereum price has been decreased by almost 10%.
Don't know what happened with Rippple but based on the graph for the recent days it seems amazing.