Hey there, I have bought several Altcoins and currelty just keep them Poloneix exchange, are there a good altcoins wallet to keep them all in one place
or is it safer just to keep each one separate in the developers wallet?
I personally never keep coins in an exchange any longer than i need to in order to buy or sell... To many exchanges went belly-up over the last years.
Offcourse, you can take your change and leave your funds at poloniex, they're a pretty old exchange, but you can never be sure.
Keeping the coins in the original wallets is probably the best thing you could do, like robelneo already said: make sure you backup your wallet.dat!!!
There are a couple in-between sollutions... I tried coinomi on my android phone once (it's a wallet that supports multiple altcoins in one wallet), it seems OK: the private keys are kept on your own device and never sent to the server... It's not as safe as a good desktop wallet tough!