I'd say AK-48, since that seems to be growing well for me. I have two Short Riders, but they're both starting to show as boys (seeing tiny bunches of balls) so I guess I'm not going to have any Short Rider to try yet. Blue Mystic is a nice strain too, and my 2 are growing beautifully, but one is looking suspiciously male - I have hopes that the other is a girl as it does not have any obvious balls yet. Of 8 plants, I have two confirmed AK-48 girls and the one Blue Mystic that I'm waiting on - the other 5 appear to be showing as males (I'm giving them another few days, just to be sure I don't trash anything by mistake). If you're looking to keep the plant short, you can always top it for multiple colas so it grows shorter and bushier. That would allow you to choose from many different strains that you might want to try. Check out Nirvanashop.com for their wide variety of seeds if you want to get a good price. They have great customer service and stealth shipping too. There are plenty of seed banks, but I like the prices at Nirvana...especially for a new grower who may waste a few seeds before they get the hang of things. It's not as bad to lose a few seeds to grower mistakes when you got a great price on them. Good Luck!