With its vivid Super AMOLED display, the Captivate Glide lends itself well to watching videos, though the screen is only 4 inches. Its Tegra 2 processor also helps considerably with HD content.
The two biggest problems you'll run into are a matter of codec compatibility and a lack storage space. The default Video doesn't like MKV containers, and depending on the codec used, won't play certain MP4s and AVIs. Alternative video players from the Android Marketplace can remedy this, though.
If you plan on playing HD videos, the 4GB of user available storage will be a big factor. Thankfully, the Glide's MicroSD port accepts cards up to 32GB in size.
It also includes Samsung's Media Hub app which allows you to purchase and rent movies to download to your device (on WiFi only unfortunately).
The Tegra 2 processor handles HD videos well, but not perfectly. 720p videos play smoothly in almost all cases, but 1080p can be problematic with codecs that can't be hardware accelerated.
Since the Glide only has an 800x480 display anyway, 1080p videos are a bit overkill – that is, unless you're using the MicroUSB to HDMI adapter or DLNA to watch it on a big screen.
With 4G capabilities, streaming movies is also an option through apps like Netfilx, assuming AT&T's network can handle it.
Even though streaming puts a heavy drain on the battery, you should be able to get through 2 full length movies with some juice to spare.
The music player not only has an attractive interface but is also very capable. It supports just about every format under the sun, including OGG and FLAC files.
It can even decode and downmix 5.1 channel sources for your stereo headphones. The only thing more we could wish for is a way to stream music from the cloud.
The Gallery app is pretty much the standard Android Gallery. It finds images and videos automatically and lists them in thumbnailed folders.
The only major feature added is the ability to zoom in and out by pressing two fingers to the screen and then tilting the phone.