I got this from Cassia Thomas, and I thought I'd give it a go.
She's doing it on Facebook too, though, but seeing as I don't have a Facebook account, I thought I'd just do it on my blog instead.
So if you do it too, put a link to it in the comments below :)
But anyway, my fifteen, (with optional subject categories as well) are -
Comics
1 - Steve Ditko
2 - Bill Sienkiewicz
3 - Alan Davis
4 - Dudley D Watkins
5 - Jamie Hewlett
Classic
6 - Arthur Rackham
7 - Mervyn Peake
8 - E H Shepherd
9 - Edmund Dulac
10 - Edward Ardizzone
Recent
11 - Barbara Firth
12 - Ross Collins
13 - Oliver Jeffers
14 - Quentin Blake
15 - Chris Riddell
The picture is Oor Wullie by Dudley D Watkins, who did the Broons, and Lord Snooty as well.
My Grandma and Grandad used to have Oor Wullie and The Broons annuals from the Dudley D Watkins era, so he's probably the earliest influence on my list.