The recent crash in the cryptospace brought down the value of coins by more than 70%, now with FUD about the bitcoin split being taken care of the BTC should be testing new all time highs, but there are many alts that gives you a good opportunity to double your BTC if you buy them right now, here is the list :
ANS/NEO: being called China's Ethereum by many, ANS is set for it's Rebranding and a press conference on Monday.
AMP: this coin took a major hit during the past 1 month, it's now being traded at around 11k satoshis, still lower than 60% from it's all time highs, with wildspark being released for everyone by august 13, the prices should only move forward from here.
OMG: this coin is new in the market and so technicals won't work on it, but with MNC's backing it up and it having a fully functional working model, this coin is very cheap right now, you can buy this now and forget about it for a while.
SC: Siacoin is less than 60% of it's value from it's ATH, if you haven't bought this yet, i would recommend that you sit on the sidelines and watch it go past 600 sats soon.
CIVIC: the idea and the technology behind this coin is impressive, it's available at a very good price and is ripe for entry.