gci . -r | sort Length -desc | select fullname -f 10
or
Get-ChildItem -Path 'C:\SomeFolder' -Recurse -Force -File | Select-Object -Property FullName,@{Name='SizeGB';Expression={$_.Length / 1GB}},@{Name='SizeMB';Expression={$_.Length / 1MB}},@{Name='SizeKB';Expression={$_.Length / 1KB}} | Sort-Object { $_.SizeKB } -Descending | Out-GridView