## Powershell, <s>57</s> <s>56</s> <s>54</s> 53 Bytes ##

The CLI in powershell will glitch out slightly on some computers, so it doens't look perfect, but it's as good as I can feasibly get.

Moved $a++ into the for loop to save one byte, (no `;`)

Then moved it into the array indexer, for another 2 byte save, thanks to Roman for pointing that out.

Also saved 1 more byte (`;`) by moving the Clear screen (`cls`) part into the for loop..

`for(;;cls){"Loading... "+"|/-\"[$a++%4];sleep -m 250}`

[![Loading Gif][1]][1]

<s>`for(;;){"Loading... "+"|/-\"[$a++%4];sleep -m 250;cls}`</s>

<s>`for(;;$a++){"Loading... "+"|/-\"[$a%4];sleep -m 250;cls}`</s>

<s>`for(;;){$a++;"Loading... "+"|/-\"[$a%4];sleep -m 250;cls}`</s>

  [1]: https://i.sstatic.net/Y8H7M.gif