Here's another list with a few more countries included. Also it lists the offical abbreviation for the country if you want to use that instead of the long name in the field

<font size="-1"> Country: </font><select name="country">
<option value="US">United States
<option value="AF">Afghanistan
<option value="AL">Albania
<option value="DZ">Algeria
<option value="AS">American Samoa
<option value="AD">Andorra
<option value="AO">Angola
<option value="AI">Anguilla
<option value="AQ">Antarctica
<option value="AG">Antigua and Barbuda
<option value="AR">Argentina
<option value="AM">Armenia
<option value="AW">Aruba
<option value="AC">Ascension
<option value="AU">Australia
<option value="AT">Austria
<option value="AZ">Azerbaijan
<option value="BS">Bahamas
<option value="BH">Bahrain
<option value="BD">Bangladesh
<option value="BB">Barbados
<option value="BY">Belarus
<option value="BE">Belgium
<option value="BZ">Belize
<option value="BJ">Benin
<option value="BM">Bermuda
<option value="BT">Bhutan
<option value="BO">Bolivia
<option value="BA">Bosnia / Herzegovina
<option value="BW">Botswana
<option value="BV">Bouvet Island
<option value="BR">Brazil
<option value="IO">Brit. Ind. Ocean Terr.
<option value="VG">British Virgin Islands
<option value="BN">Brunei
<option value="BG">Bulgaria
<option value="BF">Burkina Faso
<option value="BU">Burma
<option value="BI">Burundi
<option value="KH">Cambodia
<option value="CM">Cameroon
<option value="CA">Canada
<option value="CV">Cape Verde
<option value="XC">Catalonia
<option value="KY">Cayman Islands
<option value="CF">Central African Repub
<option value="TD">Chad
<option value="CL">Chile
<option value="CN">China
<option value="CX">Christmas Island
<option value="CC">Cocos Islands
<option value="CO">Colombia
<option value="KM">Comoros
<option value="CG">Congo
<option value="CK">Cook Islands
<option value="CR">Costa Rica
<option value="CI">Cote d'Ivoire
<option value="CT">Croatia
<option value="HR">Croatia
<option value="CU">Cuba
<option value="CY">Cyprus
<option value="CZ">Czech Republic
<option value="YD">Democratic Yemen
<option value="DK">Denmark
<option value="DG">Diego Garcia
<option value="DJ">Djibouti
<option value="DM">Dominica
<option value="DO">Dominican Republic
<option value="TP">East Timor
<option value="EC">Ecuador
<option value="EG">Egypt
<option value="SV">El Salvador
<option value="GQ">Equatorial Guinea
<option value="ER">Eritrea d
<option value="EE">Estonia
<option value="ET">Ethiopia
<option value="FK">Falkland Islands
<option value="FO">Faroe Islands
<option value="FM">Fed. St. of Micronesia
<option value="FJ">Fiji
<option value="FI">Finland
<option value="FR">France
<option value="GF">French Guiana
<option value="PF">French Polynesia
<option value="TF">Fr. So. Territories
<option value="GA">Gabon
<option value="GM">Gambia
<option value="XA">Gaza
<option value="GE">Georgia
<option value="DE">Germany
<option value="GH">Ghana
<option value="GI">Gibraltar
<option value="GR">Greece
<option value="GL">Greenland
<option value="GD">Grenada
<option value="GP">Guadaloupe
<option value="GU">Guam
<option value="GT">Guatemala
<option value="GN">Guinea
<option value="GW">Guinea-Bissau
<option value="GY">Guyana
<option value="HT">Haiti
<option value="HM">Heard &McDonald Is.
<option value="HN">Honduras
<option value="HK">Hong Kong
<option value="HU">Hungary
<option value="IS">Iceland
<option value="IN">India
<option value="ID">Indonesia
<option value="IR">Iran
<option value="IQ">Iraq
<option value="IE">Ireland
<option value="IL">Israel
<option value="IT">Italy
<option value="JM">Jamaica
<option value="JP">Japan
<option value="JO">Jordan
<option alue=KZ">Kazakhstan
<option value="KE">Kenya
<option value="KI">Kiribati
<option value="KW">Kuwait
<option value="KG">Kyrgyzstan
<option value="LA">Laos
<option value="LV">Latvia
<option value="LB">Lebanon
<option value="LS">Lesotho
<option value="LR">Liberia
<option value="LY">Libya
<option value="LI">Liechtenstein
<option value="LX">Lithuania
<option value="LU">Luxembourg
<option value="MO">Macau
<option value="MK">Macedonia
<option value="MG">Madagascar
<option value="MW">Malawi
<option value="MY">Malaysia
<option value="MV">Maldives
<option value="ML">Mali
<option value="MT">Malta
<option value="MP">Marina Islands
<option value="MH">Marshall Islands
<option value="MQ">Martinique
<option value="MR">Mauritania
<option value="MU">Mauritius
<option value="YT">Mayotte
<option value="MX">Mexico
<option value="MD">Moldova
<option value="MC">Monaco
<option value="MN">Mongolia
<option value="MS">Montserrat
<option value="MA">Morocco
<option value="MZ">Mozambique
<option value="MM">Myanmar
<option value="NA">Namibia
<option value="NR">Nauru
<option value="NP">Nepal
<option value="NL">Netherlands
<option value="AN">Netherlands Antilles
<option value="NT">Neutral Zone
<option value="NC">New Caledonia
<option value="NZ">New Zealand
<option value="NI">Nicaragua
<option value="NE">Niger
<option value="NG">Nigeria
<option value="NU">Niue
<option value="NF">Norfolk Island
<option value="NO">Norway
<option value="OM">Oman
<option value="PK">Pakistan
<option value="PW">Palau
<option value="PA">Panama
<option value="PG">Papua New Guinea
<option value="PY">Paraguay
<option value="KP">P. R. of Korea
<option value="PE">Peru
<option value="PH">Philippines
<option value="PN">Pitcairn
<option value="PL">Poland
<option value="PT">Portugal
<option value="PR">Puerto Rico
<option value="QA">Qatar
<option value="KR">Republic of Korea
<option value="RE">Reunion
<option value="RO">Romania
<option value="RU">Russia
<option value="RW">Rwanda
<option value="GS">S. Georgia &Sandwich
<option value="SH">Saint Helena
<option value="KN">Saint Kitts and Nevis
<option value="LC">Saint Lucia
<option value="PM">St. Pierre &Miquelon
<option value="VC">St. Vincent Grenadines
<option value="SP">Saipan
<option value="WS">Samoa
<option value="SM">San Marino
<option value="ST">Sao Tome &Principe
<option value="SA">Saudi Arabia
<option value="SN">Senegal
<option value="SC">Seychelles
<option value="SL">Sierra Leone
<option value="SG">Singapore
<option value="SK">Slovakia
<option value="SI">Slovenia
<option value="SB">Solomon Islands
<option value="SO">Somalia
<option value="ZA">South Africa
<option value="ES">Spain
<option value="LK">Sri Lanka
<option value="SD">Sudan
<option value="SR">Suriname
<option value="SJ">Svalbard &Jan M. Is.
<option value="SZ">Swaziland
<option value="SE">Sweden
<option value="CH">Switzerland
<option value="SY">Syria
<option value="TW">Taiwan
<option value="TJ">Tajikistan
<option value="TZ">Tanzania
<option value="TH">Thailand
<option value="TG">Togo
<option value="TK">Tokelau
<option value="TO">Tonga
<option value="TT">Trinidad and Tobago
<option value="TN">Tunisia
<option value="TR">Turkey
<option value="TM">Turkmenistan
<option value="TC">Turks &Caicos Islands
<option value="TV">Tuvalu
<option value="UG">Uganda
<option value="UA">Ukraine
<option value="AE">United Arab Emirates
<option value="GB">United Kingdom
<option value="UY">Uruguay
<option value="UM">US Minor Outlying Is.
<option value="VI">US Virgin Islands
<option value="UZ">Uzbekistan
<option value="VU">Vanautu
<option value="VA">Vatican City State
<option value="VE">Venezuela
<option value="VN">Vietnam
<option value="WF">Wallis &Fortuna Is.
<option value="EH">Western Sahara
<option value="YE">Yemen
<option value="YG">Yugoslavia
<option value="ZR">Zaire
<option value="ZM">Zambia
<option value="ZB">Zanzibar
<option value="ZW">Zimbabwe </select>