I agree that getting reminders for missed phone calls and text messages are an important and needed feature.
I use Handcent SMS by handcent_admin (Free) for my Text Messages. It offers the ability to customize every conceivable feature. In the Notification Settings area you can Enable Popups for new messages, set the Notification Sound, Notification Icon, Unread Count, Turn the Screen On, Vibrate On/Off, Vibration Pattern, Blink LED, Color of LED, LED Flash Frequency, and Enable Reminders setting the Number of Reminders, Reminder Interval, Turn Screen On for Reminders and set a Special Reminder Sound. I can't think of anything else you could ask for.
For Missed Calls: the phone will give you a reminder in the notification bar, but that's all. I use Missed Call for Android 2.x by Anno (Free). It allows you to set LED On/Off, LED Color, LED Interval, Vibration On/Off, Vibration Pattern, Sound On/Off, Sound File, Repeats On/OFf, and Repeat Pattern. You can even have unique reminder settings for individual Contacts. Again, I think this one covers it completely.