LLC members are taxed on their personal tax returns. The LLC itself is not taxed. S-Corp shareholders are taxed on their personal tax returns. The company itself is not taxed. C-Corps are taxed both at the corporate level and again on shareholders' individual returns. Non-Profits are taxed on a corporate level but may also enjoy a host of tax-exempt benefits. Sole Proprietorships are taxed only on their owner's tax return.
LLP, Limited Liability Partnership: a partnership where a partner's liability for the debts of the partnership is limited except in the case of liability for acts of professional negligence or malpractice. In some states, LLPs may only be formed for purposes of practicing a licensed profession, typically attorneys, accountants and architects. This is often the only form of limited partnership allowed for law firms (as opposed to general partnerships).
The "mit beschränkter Haftung (mbH)" suffix (German: [ˈɛmbeːˌhaː], "with limited liability") is sometimes added to the name of a firm that already ends in "-gesellschaft" ("company"), e.g., "Mustermann Dental-Handelsgesellschaft mit beschränkter Haftung" ("dental trading company with limited liability"), which would be abbreviated as "Mustermann Dental-Handelsgesellschaft mbH".