Tryfan

Miko

The South ridge is a little easier (except for the final step onto the summit where there is an exposed drop on the east side) but as scrambling goes, the North Ridge is pretty straightforward, and (although it can be difficult to find), there is a path for a lot of the distance that avoids most of the aggressive scrambling.

If you're going on a sunny weekend day in the summer the route will be busy so it is quite easy to watch people ascend the more tricky steps, and follow on / ask advice.

So.... assuming you're generally fit and experienced at general hill walking, have a full day to do it in and good weather I wouldn't necessarily shy away from going up the North Ridge - just start early, take your time, and be prepared to go and look at steps but back away and find an easier route if you're not happy.

If you want the easiest and most obvious route then I would say it must be the south ridge from Idwyl Cottage

From the Ogwen Valley Mountain Rescue Organisation web site:

"Two brothers had climbed the North Ridge of Tryfan but stopped before the summit due to low cloud and poor weather conditions. On their way back down the ridge they strayed to the West and became lost and confused on the broken ground just above the Milestone Buttress. After several attempts to find the route they called for help. It was a very quick job for a party of four team members to walk to their location and escort them back to the road."

If you are inexperienced I'd suggest picking a clear day for your first attempt. Scrambling down is trickier than scrambling up, and it is much easier to wander off route on the way down. Have fun!