Here's one for Solitaire buffs. This app contains 19 different versions of Solitaire: Aces , Aces up, Alaska, Australian Patiance, Beleagured Castle, Calculation, Canfield, Cruel, FreeCell, Golf, Klondike, Osmosis, Pyramid, Russian Solitaire, Scorpions, Shamrock, Spider, Ukranian Solitaire, and Yukon.

Well designed game play with lots of shortcuts to reduce the number of key presses needed to play. Clear graphics make it easy to tell the suits and card values apart.

Good help screens explaining the rules of each game and describing the key mappings which seem to work as documented on both CDMA and iDEN phones except that you the OK key doesn't work on the iDEN phones (use the Call key as OK).

Type: Ad-supported
Vendor:
Publisher: ZGroup Mobile
Data Connection Required: Yes
Minimum Java ME profile: MIDP 2.0
Screen Size: 176x220 (not playable on smaller screens)
Boost CDMA Compatible: (tested on Motorola Rambler):  Yes
Boost iDEN Compatible: (tested on i776): Yes
Supported iDEN phones: All Falcon series with Java and 176x220 or larger screens  (i475,  i9,  i856, etc.)

The app "NineteenSol" (120 KB) is ready to download or send to your phone as filename:"19Solitaire".

I found an ad supported version of the commercial game "Wingames 3 in 1" that Irina requested last week .It combines high quality versions of Freecell, Spider Solitaire and Minesweeper. The games have great graphics, nice animations and working sound. There is a minor problem with the softkey mappings but there's an easy work around.

Keys:
Press the right softkey to perform the left softkey's action.
Press the menu key to perform the right softkey's action.
Use the Call key as the OK key

Type: Ad-Supported
Vendor: HeroCraft
Data Connection Required: Yes
Supported iDEN phones: All Falcon Series with Java. Best on phones with 128x160 screens  )i465 and i776)
File Size: 130 KB

A nice implementation of FreeCell Solitare with clear graphics and a responsive user interface.  It's ad supported. There's one text  ad at the start of the game which does take 30 seconds or so to download but doesn't really bother me. Use the green "Call" key as the OK button to pick up and drop cards. There's no online help, if you don't know the rules or are looking for some tips I recommend this FreeCell Tutorial

Type: Ad Supported
Vendor: Hovr - Product Page
Data Connection Required: Yes
Supported iDEN phones: All Falcon Series (i776, i465, i9, i290, etc.)