The views from Snowdon's summit can be spectacular on a clear day—you just shouldn't expect to be rewarded with them on your trip. As typical in this part of the UK, the weather can turn at a moment's notice, so pack a raincoat regardless of the weather forecast, and be prepared to get your kicks from the climb—not the view.
The summit is home to a fantastic summit station, complete with tea, coffee, beer and cider, and tons of merchandise if you're into that sort of thing. You can also get tickets for the train that'll take you back down the mountain, just prepare to part with £20 for the privilege. If you do take the train, it'll drop you out in the village of Llanberis, from where the Snowdon Shuttle will take you back to your car if you came up one of the other paths. Spot for a quick coffee or a beer on the summit. You can also buy train tickets here, just be warned: they're not cheap. A single adult ticket back down the mountain costs £22.
The top of the world! If you're in Wales, anyway. The view from the top is cracking when the weather's good, but we didn't have such luck on our trip. To snap a photo of the summit cairn, you may have to stand in line.
Great spot on a clear day. All those that are not able to climb can take the train and meet you at the cafe. Check the weather forecast before you climb if you want a view. The weather can change very quickly up there.