First of all, Bitcoin is increasing its market dominance steadily and therefore I think that it may be a good idea to purchase some BTC after converting your alts (especially ETH and XRP). Other coins that look attractive includes ADA and NEO.
I don't think that converting our alts especially now in a pretty dumped market is the right choice as we will be facing a major financial loss due to selling alts in dumped market, so the best case scenario is that if you are having any spare money left then you should buy bitcoins from that amount of money as in this case you wouldn't be loosing any money at all.