Here are a few ways to set quotes apart from the other content on your slides or to make it more interesting when it's the only message on a slide. The download has all of the variations in all the orientations.
Customizing the quote variations
Place the start quote group and then the end quote group on the sides or above and below the quote text (depending on which set you're using). You can rescale the start and end quote graphics to your liking. you can also reduce/increase the length of the line as you wish as well.
You can also rescale the quote layout by grouping it and resizing it holding the shift key down. The quotation marks will rescale since they are not text objects.
Color variationsThe colors of the quote graphics are muted, almost tone on tone so, that the most prominent part of the quote layout is the text. You can change the colors of the circle/square and/or the quotation marks by applying a fill color of your choice.
No 3D. The 3D will add too much bulk to the graphic and possibly overpower the quote text. You don't want that.
Shadows might be okay, but not if you're using PowerPoint 2003.
Gradients, patterns, and pictures
None of these are needed.
You can animate with simple reveals with the quote text if you want.